Open access peer-reviewed chapter

Hyaluronic-Based Antibacterial Hydrogel Coating for Implantable Biomaterials in Orthopedics and Trauma: From Basic Research to Clinical Applications

Written By

Giammona Gaetano, Giovanna Pitarresi, Palumbo Fabio Salvatore, Maraldi Susanna, Scarponi Sara and Romanò Carlo Luca

Submitted: June 11th, 2017 Reviewed: December 18th, 2017 Published: February 2nd, 2018

DOI: 10.5772/intechopen.73203

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Edited by Sajjad Haider and Adnan Haider

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Bacterial colonization of implanted biomaterials remains one of the most challenging complications in orthopedics and trauma surgery, with extremely high social and economic costs. Antibacterial coating of implants has been advocated by many experts as a possible solution to reduce the burden of implant-related infection and several different solutions have been proposed in the last decades. However, while most of the investigated technologies have shown their efficacy in vitro and/or in vivo, only few were able to reach the market, due to clinical, industrial, economic and regulatory issues. Hyaluronic acid composites have been previously shown to possess antifouling capabilities and have been used in various clinical settings to reduce bacterial adhesion and mitigate biofilm-related infections. Recently, a fast-resorbable, hyaluronic-based hydrogel coating was developed to protect implanted biomaterials in orthopedics, trauma and maxillofacial surgery. Preclinical and clinical testing did show the safety and efficacy of the device that can be intraoperatively loaded with one or more antibiotics and directly applied by the surgeon to the implant surface, at the time of surgery. Here, we review the current evidence concerning this very first antibacterial coating of implants and outline the economic impact of the possible large-scale application of this technology.


  • coating
  • hydrogel
  • hyaluronic acid
  • DAC
  • infection
  • implant
  • orthopedic
  • trauma
  • prosthesis
  • prevention

1. Introduction

Up to 80% of human bacterial infections are biofilm-related, according to the U.S. National Institutes of Health [1]. Among these, implant-related infections in orthopedics and trauma still have a tremendous impact [2]. In fact, periprosthetic joint infection (PJI) (Figure 1) is among the first reasons for implant failure [3], posing challenging diagnostic and therapeutic dilemmas [4] and with high economic and social costs [5, 6, 7].

Figure 1.

Infected, exposed, knee prosthesis in a 60-year-old woman. Approximately one million joint replacements are performed annually in Europe, and infection is currently among the first three most common reasons for failure of implants. Septic complications are associated with prolonged and complex medical and surgical treatments, often leading to implant removal. Poor functional results, possible infection recurrence, risk of amputation and increased mortality rate are all well known and feared consequences of periprosthetic and implant-related infections. Direct costs of treatment of periprosthetic infection exceeds 100,000 euros, per case, according to a recent analysis [7].

Similarly, surgical site infections after osteosynthesis, with a reported incidence ranging from 3.9 to 10% for closed fractures [8, 9, 10, 11] and even more after open fractures [12], are associated with high morbidity and possible mortality raise [9] and elevated costs [13].

Whenever a biomaterial is implanted, a competition between host and bacterial cells occurs for surface colonization. In the event of bacterial adhesion to an implant, immediate biofilm formation starts, making the bacteria extremely resistant to host’s defense mechanisms and to antimicrobials [14, 15, 16]. According to recent evidence, fully formed biofilm can be found few hours after the first bacterial adhesion [17]; thus, the destiny of an implant is decided at the very time of surgery.

To reduce or prevent bacterial adhesion and biofilm formation, a number of different antimicrobial finishing or coatings of implants are under study [18]. However, their clinical application appears particularly challenging, due to the many requirements they need to fulfill [19].

Hyaluronic acid (HA) is mucopolysaccharide, occurring naturally in mammals. It is abundant in skin and in connective tissues, being one of the main components of extracellular matrices. HA has several clinical applications in dermatology, esthetic surgery, dentistry, urology, orthopedics and ophthalmology [20]. In fact, due to its high biocompatibility, and nonimmunogenicity, hyaluronic acid is considered as an ideal biomaterial for medical and pharmaceutical applications [21, 22].

Local application of hyaluronic-based compounds has been demonstrated to be protective against various infectious agents, depending on HA concentration and molecular weight; furthermore, HA’s ability to reduce bacterial adhesion and biofilm formation has been recently reported [23].

High biocompatibility, safety profile and antiadhesive properties make HA and its composites a possible non-antibiotic option to reduce the impact of biofilm-related infections in various clinical settings. However, the use of HA in its pure form as an antibacterial coating does not appear suitable, due to its rapid degradation by hyaluronidases, enzymes naturally occurring in the human and animal body. Furthermore, due to its high hydrophilicity, a coating produced with a hydrogel of HA alone would not have sufficient mechanical stability when a prosthesis is implanted in the body, which is an essentially water-based environment.

To overcome these limits, a combination of HA with another biocompatible and biodegradable polymer, polylactic acid (PLA), was investigated [24]. In fact, PLA is a synthetic polyester, approved in the U.S.A. by the Food and Drug Administration (FDA) and widely used for orthopedic implants [25]. PLA unlike HA, shows a hydrophobic character; therefore, its presence could be exploited to control in appropriate way the hydrophilic and mechanical properties of a hydrogel based on HA, thus slowing down the susceptibility to hydrolysis.

Here, after an overview of the antiadhesive and antibiofilm properties of HA, we summarize the development of a CE-marked, patented hydrogel coating, based on HA grafted to PLA (DAC®, “Defensive Antibacterial Coating,” Novagenit Srl, Mezzolombardo, Italy). Some of the most relevant preclinical and clinical results that made this device the very first resorbable antibacterial coating for large-scale clinical applications in orthopedic, trauma, dentistry and maxillofacial implants are also briefly reported.


2. Antiadhesive and antibiofilm properties of HA

Pavesio et al. [26] were probably the first to describe HA nonfouling properties and its ability to resist bacterial adhesion, with particular reference to Staphylococcus epidermidis [27], proposing coated polymeric medical devices to reduce implant-related infections. In particular, a hydrophilic HA overlayer, linked to the surface of polymethylmethacrylate intraocular lenses (IOLs), was shown to be able to significantly reduce the adhesion of Staphylococcus epidermidis to the implant surface [28].

In line with this observation, Kadry and coworkers, reported the ability of hyaluronan to reduce bacterial adhesion to IOLs of a S. epidermidis wild strain [29]; based on these findings, the authors proposed the use of HA as an antiadhesive, adjuvant therapy, in combination with antibiotics in irrigating solutions for bacterial ocular infections.

More recently, Drago et al. reported on the in vitro antiadhesive and antibiofilm activity of HA toward bacterial species commonly isolated from respiratory infections [30]. In this experimental study, HA was shown to be able to reduce bacterial adhesion to a cellular substrate in a concentration-dependent manner. The antibiofilm action, exerted by HA in ear, nose and throat districts, has been recently reviewed [31]. The authors conclude that “its efficacy in treating rhinosinusitis, whether or not associated with polyposis, is well documented, as well as results from its effects on mucociliary clearance, free radical production and mucosal repair.”

HA has also been reported to exert bacteriostatic, dose-dependent effect on different planktonic microorganisms [32, 33]. Radaeva et al. showed the inhibiting activity of HA with respect to some Pseudomonas species [34], while Ardizzoni and coworkers [23] investigated the effects of HA on 15 ATCC bacterial strains, representative of clinically relevant bacterial and fungal species. According to their results, different microbial species and strains are differently affected by HA. In particular, staphylococci, enterococci, Streptococcus mutans, two Escherichia coli strains, Pseudomonas aeruginosa, Candida glabrata and C. parapsilosis showed a dose-dependent growth inhibition, while no HA effects were detected in E. coli ATCC 13768 and C. albicans, and S. sanguinis was favored by the highest HA dose.

Carlson and coworkers [33] compared the potential bacteriostatic effect of collagen type I, hyaluronic acid, hydroxyapatite, polylactic acid and polyglycolic acid on some of the most common orthopedic bacterial pathogens (S. aureus, S. epidermidis, β-hemolytic Streptococcus and Pseudomonas aeruginosa): HA had the most significant bacteriostatic properties on the studied organisms. Similarly, Pirnazar et al. [32] did demonstrate the bacteriostatic effect of HA in different concentrations and molecular weight on oral and nonoral microorganisms (Staphylococcus aureus, Propionibacterium acnes, Actinobacillus actinomycetemcomitans, Prevotella oris and Porphyromonas gingivalis). The authors concluded that the clinical application of hyaluronan in the form of membranes, gels or sponges may reduce bacterial contamination of the surgical wound, thereby lessening the risk of postsurgical infection and promoting more predictable regeneration.

Concerning orthopedic applications, Harris and Richards [35] showed how coating titanium with sodium hyaluronate significantly decreased the density of S. aureus adhering to the surfaces and proposed its potential use to protect osteosynthesis, orthopedic or dental implants.

In a recent review, focused on the use of polysaccharide-based coatings to prevent biofilm formation, hyaluronic acid was discussed as one of the most promising [36]; displaying hydrophilic characteristics, this coating was in fact reported to reduce adhesion of S. aureus, S. epidermidis and E. coli by several orders of magnitude compared to unmodified surfaces.


3. Clinical applications of HA to prevent bacterial adhesion

Several clinical local applications of HA to reduce the impact of biofilm-related infections have been reported with favorable results and no adverse events [37].

Torretta et al. [38] recently described topical administration of hyaluronic acid in children with recurrent or chronic middle ear inflammations and chronic adenoiditis.

Other studies have documented the positive effect of topical HA in chronic urinary tract infections (UTI). At variance with current antibiotic treatments, aimed at eradicating pathogens, HA local administration targets bacterial adherence to the bladder mucosa [39, 40, 41, 42]. Damiano et al., in a prospective, randomized, double-blind, placebo-controlled study, showed a significant reduction of 77% (P < 0.0002) in the UTI rate per year in HA-treated patients, compared to controls. Moreover, mean time to UTI recurrence was significantly prolonged (185.2 ± 78.7 vs. 52.7 ± 33.4 days, P < 0.001) after HA treatment, compared with placebo [43]. No adverse events were reported. A recent multicenter European study confirmed the efficacy of intravescical administration of combined HA and chondroitin sulfate (CS) for the treatment of female recurrent urinary tract infections [44].

In dentistry, the effect of the application of HA-containing gels in early wound healing after scaling and root planing (SRP) on clinical variables, subgingival bacteria and local immune response was investigated [45, 46]. Eick et al. [47] reported on 34 individuals affected by chronic periodontitis and treated with full-mouth SRP; in the test group (n = 17), a 0.8% hyaluronan-containing gel was introduced into all periodontal pockets during SRP and a 0.2% HA gel was applied by the patients onto the gingival margin twice daily during the following 2 weeks, while the control group (n = 17) was treated with SRP only; no placebo was used. Probing depth (PD) and clinical attachment level (CAL) were recorded at baseline and after 3 and 6 months, and subgingival plaque and sulcus fluid samples were taken for microbiologic and biochemical analysis. The changes in PD and the reduction of the number of pockets with PD ≥ 5 mm were significantly higher in the test group after 3 (P = 0.014 and 0.021) and 6 (P = 0.046 and 0.045) months. Six months after SRP, the counts of Treponema denticola were significantly reduced in both groups (both P = 0.043), as were those of Campylobacter rectus in the test group only (P = 0.028). Prevotella intermedia and Porphyromonas gingivalis increased in the control group. No adverse effects of HA were observed during the study.


4. Synthesis of DAC® HA-g-PLA hydrogel coating

Composed of covalently linked hyaluronan and poly-d,l-lactide, the “Defensive Antibacterial Coating” (DAC®, Novagenit Srl, Mezzolombardo, Italy) was specifically developed in order to protect implanted biomaterials used in orthopedics, traumatology, dentistry and maxillofacial surgery from bacterial colonization [24, 48] (Figure 2).

Figure 2.

DAC® HA-g-PLA, fast-resorbable, hydrogel coating. Composed of covalently linked hyaluronan and poly-d, l-lactide, the “Defensive Antibacterial Coating” (DAC®, Novagenit Srl, Mezzolombardo, Italy) is the first antibacterial-coating cleared for clinical use in orthopedics, trauma, dentistry and maxillofacial surgery in Europe.

Preparation of the hydrogel was performed according to a patented procedure [49]. In particular, HA-g-PLA copolymer was dispersed in an appropriate volume of twice distilled water, and the mixture was stirred vigorously at the vortex to obtain a gelatinous and transparent hydrogel with a polymer concentration between 3% (w/v) and 10% (w/v).

The synthesis of HA-g-PLA copolymer was performed as previously reported [50, 51] (Figure 3). Briefly, a low weight–average molecular weight HA (HALMW) was made soluble in organic solvents by transformation to its tetrabutylammonium (TBA) salt. The synthesis of the N-hydroxysuccinimide (NHS) derivative of PLA (i.e., PLA-NHS) was performed as reported elsewhere [52]. In particular, 2.4 g of PLA was dissolved in 30 ml of anhydrous dichloromethane with an excess of DCC and NHS for 24 h at room temperature, and then the solution was precipitated in ethanol and the recovered solid was dried under vacuum. 1H NMR of PLA-NHS (CDCl3) showed: δ 1.5 and δ 1.6 (d, 3H, ─O─CO─CH(CH3)─OH; d, 3H, ─O─CO─CH(CH3)─O─), δ 2.80 (m, 4H, ─OC─CH2─CH2─CO─); δ 4.3 and δ 5.2 (m, 1H, ─O─CO─CH(CH3)─OH; m, 1H, ─O─CO─CH(CH3)─O). The synthesis of HA-g-PLA copolymer was carried out as follows: 600 mg of HA-TBA was dissolved in 48 ml of anhydrous dimethyl sulfoxide (DMSO) and then 576 μl of DEA, as a catalyst, was added. A suitable amount of PLA-NHS (dissolved in 6 ml of anhydrous DMSO) was added according to X = 1, X being equal to moles of PLA-NHS/moles of HA repeating units. The PLA-NHS solution was added drop by drop to the HA-TBA solution in about 1 h. The reaction was carried out under argon at 40°C for 24 h. After this time, the TBA was exchanged with Na+ using a Dowex 50 W × 8-200 resin, and then the eluate was dialysed against distilled water, by using spectra/por tubing with a cutoff of 14,000 Da and then freeze-dried. The sample has been characterized by FT-IR and 1H NMR analyses. FT-IR spectrum (KBr) of HA-g-PLA showed a broad band centered at 3450 cm−1 (ν as OH + ν as NH of HA), bands at 1757 (ν as COO of PLA), 1623 (amide I of HA), 1456 (δ as CH3 of PLA), 1382 (δ as CH3 of PLA), 1189 (ν as C─O─C ester group of PLA), 1089, 1048 (ν C─O alcoholic and ether of HA) cm−1. 1H NMR of HA-g-PLA (DMSO-d6/D2O 90:10) spectrum showed: δ 1.25 and δ 1.45 (2d, ─O─CO─CH(CH3)─O─ of PLA); δ 1.85 (s, 3H, ─NH─CO─CH3 of HA) δ 5.1 ppm (m, ─O─CO─CH(CH3)─ of PLA). The % degree of grafting (DG) has been calculated as: %DG = (moles PLA chains/moles of HA repeating units) × 100. The degree of grafting was determined by comparing the integral of the peaks at δ 1.25–1.45 attributed to protons of methyl groups of PLA with the integral of peaks at δ 1.85 attributed to protons of NHCOCH3 belonging to N-acetylglucosamine residue of HA and resulted to be 7 ± 1 mol%.

Figure 3.

Principal steps in the synthesis of HA-g-PLA copolymer.


5. DAC® hydrogel in vitro activity

5.1. Cell compatibility assay

In vitro cell compatibility of DAC® HA-g-PLA hydrogel (polymer concentration 6%, w/v) was evaluated using human dermal fibroblasts. The viability of cells cultured in direct or indirect contact with HA-g-PLA hydrogel was comparable with that of the control well, showing that the hydrogel does not release in the culture medium substances that interfere with cell viability and they do not cause a decrease in the cell viability after direct contact with them [24]. Further in vitro and in vivo biocompatibility studies were performed on the DAC® hydrogel and on the DAC® kit, in accordance to ISO standards, all showing no cytotoxicity, genotoxicity, sensitization, irritation or intracutaneous reactivity, systemic toxicity (acute), subchronic toxicity or interference with bone or periimplant tissues.

Furthermore, as degradation of DAC® HA-g-PLA hydrogel occurs via deesterification of hyaluronic acid and polylactic acid, it gives raise exclusively to the starting macromolecules, whose degradation pathways in the human body are widely known and whose use as implantable class III medical devices is largely accepted and tested safe.

5.2. Antiadhesive and antibiofilm activity

Both the ability of the DAC® HA-g-PLA hydrogel to reduce bacterial adhesion and biofilm formation were extensively studied in vitro.

Reductions of adhered bacteria on sterile titanium discs, coated with DAC® hydrogel, equal to 86.8, 80.4, 74.6 and 66.7% vs. untreated discs were observed after 15, 30, 60 and 120 min of incubation, respectively [37]. In another experiment, the ability to dislodge previously adhered bacteria was investigated. Once again, the results showed that DAC® hydrogel treatment of discs reduced the amount of adhered bacteria in respect to control discs after 15, 30, 60 and 120 min by 84.0, 72.8, 72.3 and 64.3%, respectively [37].

Concerning more specifically the antibiofilm activity, DAC® hydrogel showed similar or superior in vitro activity, compared to various antibacterials and a synergistic activity when used in combination [48]. In one experimental setting, S. epidermidis and S. aureus were grown on chrome-cobalt devices in 6-wells polystyrene plates containing TSB for 24 h at 37°C. The plates were incubated at 37°C in ambient air, until a visible biofilm was obtained. Gentamycin and vancomycin were tested at a final concentration of 20 mg/mL. Similarly, when mixed with the hydrogel, 60 mg of gel powder was reconstituted with 1 mL of water for injections containing gentamicin or vancomycin at 20 mg/mL concentration. The amount of biofilm at each time was determined before hydrogel and antibiotic agents’ addition and after 0.5, 1, 2, 4, 6, 24 and 48 h of incubation by a spectrophotometric assay. At each time point, both gentamicin and vancomycin showed only a partial inhibition of biofilm formation (ca. 30–40% for gentamicin; ca. 40–50% for vancomycin), with minor difference between the two studied microorganisms. On the other side, the hydrogel alone resulted in a significant reduction of biofilm of ca. 50%, in comparison to the untreated controls, while a combination of the hydrogel with either antibacterial coating resulted in a larger reduction of biofilm formation (approximately 75–80% in comparison with untreated controls).

Both these experimental studies show the ability of the DAC® hydrogel to significantly reduce bacterial adhesion and biofilm formation of common bacterial pathogens, thus potentially providing an effective protection of the implant; however, these data also point out how, in the clinical setting, in the absence of an adequate immune response from the host and/or of sufficient local levels of antibiotics, a passive antiadhesive coating [18] like HA can be overcome by the remaining bacteria in a time-dependent manner. For this reason, any passive antiadhesive coating of implants [53] should probably better be seen as a tool to reduce and delay bacterial adhesion and biofilm formation to a variable degree, also depending on the local environment, the contaminating bacterial species and initial bacterial load; this activity of the coating may represent a key additional advantage to the host’s cells to win the competition with the microorganisms that may eventually be present. However, the known intrinsic limits of all passive coatings ground the idea of adding antibacterial agents to the protective hydrogel, in order to minimize the possibility for planktonic bacteria, which may eventually remain in the local environment, to colonize the implant at a second stage, when the coating has been hydrolyzed or covered by host’s proteins.

5.3. Antibiotic release studies

Although designed as a “stand alone” product, the DAC® hydrogel was also tested concerning its ability to entrap and eventually release locally various antibacterial agents. As outlined above, the rationale for this combination lies in the pathogenesis of implant-related infections and on the specificities of passive protective coatings. In fact, biofilm formation is a multistep process that schematically includes the bacterial adhesion to a substrate, the subsequent immediate release of signals from adherent bacteria that triggers biofilm production and, finally, the biofilm construction and progressive consolidation. Acting mainly as a physical and antiadhesive barrier, DAC® hydrogel may reduce or prevent the first phase of the process, provided that the number of living bacteria is not too high and that they are not able to overcome or hydrolyze the hydrogel [54]; moreover, for an effective prevention of bacterial colonization of the coated implant, it is necessary that, while bacteria are in the more vulnerable planktonic state, they are completely removed or killed by the host’s immune system and/or by the local chemicophysical environment. This is why, even in the presence of DAC® coating protection, systemic antibiotic prophylaxis is still to be considered necessary. In fact, if not eliminated, the remaining floating microorganisms may successfully colonize the implant once the protective coating has been hydrolyzed (a phenomenon that is expected to happen normally within 3 days from application for the DAC hydrogel) or after the implanted biomaterial has been covered by host’s proteins (fibrin, fibronectin, etc.), which may also work as suitable for bacterial adhesion. In this scenario, the possibility to add also an antibacterial drug to the coating may further contribute to reduce the planktonic microorganisms, enhancing the overall protection offered by the DAC hydrogel (Figure 4).

Figure 4.

Rationale for intra-operative mixing of DAC® hydrogel coating with antibacterial agents. Schematic representation of different scenarios. (a) Noncoated implants may get colonized by biofilm-forming bacteria (yellow circles) and infection will develop. (b) Antiadhesive coating may reduce/prevent bacterial adhesion, while the immune system (orange circles and red stars) and the systemically administered antibiotics (blue star) kill planktonic microorganisms. (c) However, if bacterial load is large enough, or if immune response and local antibiotic levels are inadequate, surviving bacteria may eventually colonize the implant, once the coating has been hydrolyzed or covered by host’s proteins. (d) To prevent this, the antibacterial hydrogel may be loaded, at the time of surgery, with antibiotic agents (blue stars) that may be locally released, contributing to eliminate all remaining planktonic bacteria.

To test the hydrogel ability to entrap antibacterial drugs, vancomycin and tobramycin had been originally chosen as examples of antibiotic molecules [24]. Both these antibiotics have been added to the hydrogel just before its use, a solution that offers several advantages. First of all, this allows to add the antibiotic when it is needed, thus avoiding the problems of shelf-life and any long-term compatibility with the hydrogel; secondly, in this way, it is possible to choose the optimal antibiotic in the specific case, taking into account the patient’s specificity (e.g., known intolerances to specific antibacterial agents) or of the specific intervention; finally, the dosing of the antibacterial agent on a case-by-case basis can be decided by the clinician. The results of the in vitro study clearly showed how the investigated antibacterial hydrogel coating, applied on a titanium disc, at a concentration in polymer in the range 2–8% (w/v) and a concentration in drug equal to 1 or 2% (w/v) is able to release vancomycin or tobramycin, or of their association, for up to 72 h, with an amount of drug released that is hundred or thousand times higher than the minimum inhibitory concentration (MIC), in a time- and dose-dependent manner.

Similar results were founded by testing several other antibacterial compounds or their combinations, including vancomycin, teicoplanin, rifampicin, daptomycin, tigecycline, cefazolin, gentamicin, tobramycin, amikacin, meropenem, levofloxacin, etc. (cf. Figure 5), at concentrations ranging from 2 to 10% [48].

Figure 5.

Tigecycline-loaded DAC® hydrogel coating, applied at surgery on a knee revision prosthesis. The hydrogel, which comes in a powder form, in a prefilled syringe, is designed to be reconstituted at the time of surgery with water for injection. The surgeon may decide to add a single or a combination of antibiotics to the water for injection, to further enhance implant protection.

In summary, all examples reported above show that DAC® hydrogel is potentially able to entrap and release suitable quantities of antibacterial agents just after the implant of the coated prosthesis. The high initial burst effect of the released drug may ensure the most efficient action at the time that is critical for the destiny of the biomaterial. Moreover, during the entire drug release period, the antibiotic concentration released by the hydrogel remains greater than MIC, thus further ensuring effectiveness of the drug released in proximity to the prosthesis.

5.4. DAC® hydrogel coating ability

For any device candidate to act as a coating of orthopedic and trauma biomaterials, mechanical adherence to the implant surface plays a key role. In particular, DAC® hydrogel has been designed to be spread manually at the time of surgery and to not interfere with the usual surgical techniques of press-fit insertion of an implant. The ability of DAC® hydrogel to completely cover even sand-blasted titanium surface and resist scraping has been confirmed by scanning electron microscopy (SEM) analysis [37]. This is an important requirement in order to reduce the exposed surface of a biomaterial, thus creating a uniform coating of the surface and leaving no pores or cracks that could eventually be colonized by planktonic bacteria.

The resistance to scraping and declothing has also been tested in the animal model and in human femurs, simulating a press-fit insertion of a cementless implant [24, 48]. Both studies demonstrated the ability of the hydrogel coating to resist insertion, with 60% to more than 80% of the hydrogel remaining adherent to the entire implant surface, while the remainder being retrieved along the inner surface of the medullary canal.


6. DAC® hydrogel in vivo activity

Safety and efficacy of the DAC® hydrogel have been investigated in several animal studies.

Concerning efficacy, in an acute model of highly contaminated implant-related infection in the rabbit, Giavaresi and coworkers [55] found that a vancomycin-loaded DAC® coating was associated with local bacterial load reduction ranging from 72 to 99%, compared to uncoated controls.

In another large investigation in the rabbit model, Boot et al. [56] showed, at longer follow-up and without systemic antibiotic prophylaxis, the ability of vancomycin-loaded DAC®-coated implants to significantly resist infection, compared to uncoated controls. Both studies did also reveal the absence of local or systemic side effects. In line with this observation, a more recent paper, focused on the impact on bone healing and implant osteointegration, reported no detrimental effects of vancomycin-loaded DAC® or of DAC® alone [57].

Another study on a rat model of acutely infected osteosynthesis did provide evidence that vancomycin-loaded DAC®-coated plates and screws not only are associated with a significant reduction of infection but also protect from the occurrence of septic nonunion, compared to uncoated implants [58]. This study is the very first demonstration that bone healing in a contaminated fracture can be improved by using an osteosynthesis coated with a fast-resorbable, antibiotic-loaded hydrogel.


7. Clinical results and applications

The DAC® hydrogel received the CE mark at the end of year 2013. The available kit ( or is composed of a prefilled syringe, containing 300 mg sterile DAC® powder, that is filled at surgery with a solution of 5 mL sterile water for injection, eventually mixed with the desired antibiotic(s); this allows to obtain, in approximately 3–5 min, the antibiotic-loaded hydrogel, at a DAC® concentration of 6% (w/v) and at an antibiotic concentration usually ranging from 20 mg/mL to 50 mg/mL, depending on the surgeon’s choice. The surgeons can choose the antibiotic from among a list of antibacterials previously tested as being compatible with the hydrogel (Novagenit SRL, data on file). A few minutes after reconstitution, the hydrogel can be directly spread onto the implant, which is then inserted into the body in the usual way. If necessary, once reconstituted, the hydrogel may remain at ambient temperature for up to 4 h.

Two large multicenter, randomized, prospective clinical trials were undertaken in Europe, within the 7th European Framework Programme (project # 277988), funded by the European Commission.

In a first trial, a total of 380 patients, scheduled to undergo primary (n = 270) or revision (n = 110) total hip (N = 298) or knee (N = 82) joint replacement with cementless or hybrid (partially cemented) implants were included [59, 60]. The patients were randomly assigned, in six European orthopedic centers, to receive an implant either with the DAC® coating, intraoperatively loaded with antibiotics (treatment group), or without the coating (control group). Pre- and postoperative assessment of clinical scores, wound healing, laboratory tests and X-ray exams were performed at fixed time intervals. Overall, 373 patients were available at a mean follow-up of 14.5 ± 5.5 months (range 6–24). On average, a volume of 8.3 mL hydrogel was used to coat an implant. The most often used antibiotics were vancomycin and gentamicin at a concentration of 5% and 3.2%, respectively. Fifteen patients received an implant with a combined vancomycin and meropenem antibiotic coating; four patients received an implant coated with teicoplanin 5% or ceftazidime 5% or amphotericin B 5%, all in a second-stage procedure for previous infection. Eleven surgical site infections were observed in the control group and only one in the treatment group (6% vs. 0.6%; P = 0.003). No local or systemic side effects related to the DAC® hydrogel coating were reported and no detectable interference with implant osteointegration was noted.

In the other multicenter, prospective study, 256 patients, undergoing osteosynthesis for a closed fracture, were randomly assigned, in 5 European orthopedic centers, to receive the antibiotic-loaded DAC® coating or to a control group, without coating. At a mean follow-up of 18.1 ± 4.5 months (range 12–30), 253 patients were available for evaluation. On average, 5.7 mL (range: 1–10 mL) of DAC® hydrogel was needed to coat the implant. Gentamicin and vancomycin were the most used antibiotics, at concentration of, respectively, 4% or 2%. Six surgical site infections (4.6%) were observed in the control group compared to none in the treated group (P < 0.02). No local or systemic side effects related to DAC® hydrogel coating were observed and no detectable interference with bone healing was reported [61, 62] (cf. Table 1).

ReferenceNumber of patientsFollow-up (months)DAC-treated SSI rate (%)Controls SSI rate (%)PSide effects
Romanò et al. [58]38014.5 ± 5.50.660.003None
Malizos et al. [60]25618.1 ± 4.504.6<0.02None

Table 1.

Summary of the main results of the published clinical multicenter trials on DAC® hydrogel coating in orthopedics and trauma.

SSI, surgical site infection.

Preliminary results of the possible use of the DAC® hydrogel coating in one-stage exchange of infected prosthesis did also recently show the efficacy and safety of the device in this challenging application [63]. Further studies are currently under way concerning joint replacement in bone tumors, spine surgery, exposed fractures and dentistry.


8. Economic impact

Periprosthetic joint infections (PJI) are associated with increased costs for public health systems, mainly due to additional surgeries, prolonged hospitalization, increased length of rehabilitation and increased use of antibiotics [64]. Moreover, PJIs are associated with an increase in morbidity and mortality [65]. Unless novel, effective measures are taken to reduce the incidence of surgical site infections (SSIs), these complications will become an accruing burden to the health care system in the next two decades [66, 67].

Cost-effectiveness of antibacterial coatings of joint prostheses can be calculated, comparing their direct and indirect hospital costs with those of unprotected implants, taking into consideration the expected surgical site infection rate and using a decision-analytic modeling approach, as previously described by Diaz-Ledezma et al. [68] and Kapadia et al. [69].

Table 2 reports an algorithm used to calculate the overall economic impact of DAC® hydrogel coating. The following variables are included for calculation: average cost and number of primary joint replacements; average cost of the antibacterial coating per patient; incidence of PJI and expected reduction of infection rate with the use of the coating; average cost of PJI treatment and expected number of cases.

Table 2.

Algorithm used to estimate the economical impact of antibacterial coating technologies.

Various scenarios can be simulated with the reported algorithm, depending on the relative value given to each variable.

Considering the undiscounted price of DAC® hydrogel at our institution of € 585.00 per package and two packages of DAC® as the standard use per patient, it can be calculated that, if the coating is able to reduce surgical site infection by 90% [60], DAC® is in economical balance if applied to a population of patients with an expected rate of septic complications (without the coating) of 2.6% (Table 3).

Table 3.

In this simulation, assuming an average cost of primary joint replacement of € 8000 per patient, an average cost of DAC® of € 1170 per case (i.e., two packages per patient), an expected reduction of postsurgical infections by using the coating of 90% and an average cost of PJI treatment of € 50,000 [6, 74], it can be calculated that DAC® is in economical balance if used in a population of patients with an expected periprosthetic infection rate, without the coating, of 2.6%.

According to a similar calculation, if applied on a large scale, to a selected population of patients with at least one risk factor for infection and an expected incidence of infection, without the coating, of 5%, DAC® would provide, in a medium size country, like Italy (approximately 160,000 joint replacements per year), annual direct cost savings of approximately € 43,200,000 (or 1080 € per patient). An expected incidence of postsurgical infection of 5% applies to patients with at least one risk factor for infection, which is at least 25% of all patients undergoing joint replacement [70, 71].

The present analysis is very conservative. One package of DAC® is in fact sufficient in the vast majority of primary implants. Secondly, recent studies point out how the long-term average cost of PJI is much higher than € 50,000, largely exceeding € 100,000 per patient [13]; finally, the algorithm does not include indirect costs, like those deriving from treatment complications, functional inability, work loss and compensation, medicolegal costs, increased mortality rate and quality of life reduction.


9. Conclusions

Biofilm- and implant-related infections represent a dramatic and increasing burden worldwide. Available data show that hyaluronic acid has a proven in vitro antiadhesive/antibiofilm effect against some of the most common pathogens, and HA has been used safely, alone or in combination with other polymers, with satisfactory results in different conditions associated with biofilm-related chronic infections. Clinical data in various applications, including dentistry, urology, wound management, dermatology and orthopedics, paved the way to the possible use of HA as a protective coating barrier of implants.

The chemical derivatization of hyaluronic acid with polylactic acid allows the formation of graft copolymers, which, when contacted with an aqueous medium, can be used to produce hydrogels, like the recently CE-marked DAC®, with appropriate characteristics for easy preparation and application at the time of surgery. Resulting medicated hydrogel is transparent, easily spreadable over a surface, like a titanium prosthesis, and has a specifically designed duration; moreover, it has proven, peculiar, antiadhesive and antibiofilm capabilities. If required, it may also be easily loaded, at surgery, with antibacterial agents that will be released over the following hours or few days in effective high local concentrations. In fact, as a passive protective barrier, DAC® hydrogel has some limits. Among others, the antiadhesive/antibiofilm effect is limited and may vary, depending on the type of the microorganism, the bacterial load, the local environment, etc.; moreover, HA protection may be neutralized by the possible ability of some bacteria to produce hyaluronidase, an enzyme that catalyzes the degradation of hyaluronic acid [52], while collagen and hyaluronan may even become possible ligands for microbial attachment in particular situations, or the coating can be covered by other host’s proteins to which bacteria may anchor [72, 73]. To overcome some of these limits, possible loading of the hyaluronic-based hydrogel with antibiotics is technically feasible and has been found safe in various preclinical and clinical settings, being a possible option for clinicians.

In fact, both in vitro and in vivo studies did confirm the safety and efficacy of the hydrogel coating with and without loaded antibacterials.

Clinical results also clearly point out the efficacy of the DAC® coating to significantly reduce early postsurgical infection after joint replacement or internal osteosynthesis, without any detectable local side effect both concerning wound and bone healing. Moreover, no changes in organ-specific serum markers or systemic unwanted effects were noted. The high biocompatibility of its basic constituents and the short time (less than 3 days) needed for a complete hydrogel resorption make the possible occurrence of longer term side effects quite unlikely.

Finally, economical consideration points out the high cost-to-benefit ratio of the large-scale use of DAC® coating, especially in a population with at least one risk factor for infection.

The versatility of the device and its safety profile may open the way to application in other surgical fields that share similar infection risk as orthopedics and trauma.


  1. 1. Roemling U, Balsalobre C. Biofilm infections, their resilience to therapy and innovative treatment strategies. Journal of Internal Medicine. 2012;272:541-561
  2. 2. Romanò CL, Romanò D, Logoluso N, Drago L. Bone and joint infections in adults: A comprehensive classification proposal. European Orthopaedics and Traumatology. 2011;1(6):207-217
  3. 3. Cats-Baril W, Gehrke T, Huff K, Kendoff D, Maltenfort M, Parvizi J. International consensus on periprosthetic joint infection: Description of the consensus process. Clinical Orthopaedics and Related Research. 2013;471:4065-4075
  4. 4. Drago L, Lidgren L, Bottinelli E, Villafañe JH, Berjano P, Banfi G, Romanò CL, Sculco TP. Mapping of microbiological procedures by the members of the International Society of Orthopaedic Centers (ISOC) for periprosthetic infections diagnosis. Journal of Clinical Microbiology. 2016;2016:1402-1403. Pii: JCM.00155-16
  5. 5. Kamath AF, Ong KL, Lau E, Chan V, Vail TP, Rubash HE, et al. Quantifying the burden of revision total joint arthroplasty for periprosthetic infection. The Journal of Arthroplasty. 2015;30(9):1492-1497
  6. 6. Romanò CL, Romanò D, Logoluso N, Meani E. Septic versus aseptic hip revision: How different ? Journal of Orthopaedics and Traumatology. 2010;11(3):167-174
  7. 7. Parisi TJ, Konopka JF, Bedair HS. What is the long-term economic societal effect of periprosthetic infections after THA? A Markov analysis. Clinical Orthopaedics and Related Research. 2017 Jul;475(7):1891-1900
  8. 8. Bonnevialle P, Bonnomet F, Philippe R, Loubignac F, Rubens-Duval B, Talbi A, Le Gall C, Adam P. SOFCOT. Early surgical site infection in adult appendicular skeleton trauma surgery: A multicenter prospective series. Orthopaedics & Traumatology, Surgery & Research. 2012 Oct;98(6):684-689
  9. 9. Berbari EF, Osmon DR, Lahr B, Eckel-Passow JE, Tsaras G, Hanssen AD, Mabry T, Steckelberg J, Thompson R. The Mayo prosthetic joint infection risk score: Implication for surgical site infection reporting and risk stratification. Infection Control and Hospital Epidemiology. 2012;33:774-781
  10. 10. Heppert V Acute infection after osteosynthesis. European Instructional Lectures. Vol. 12, 2012, 13th EFORT Congress, Berlin, Germany. Springer Science & Business Media Ed. 2012. pp. 25-31. ISBN: 3642272932, 9783642272936
  11. 11. Keene DJ, Mistry D, Nam J, Tutton E, Handley R, Morgan L, Roberts E, Gray B, Briggs A, Lall R, Chesser TJ, Pallister I, Lamb SE, Willett K. The ankle injury management (AIM) trial: A pragmatic, multicentre, equivalence randomised controlled trial and economic evaluation comparing close contact casting with open surgical reduction and internal fixation in the treatment of unstable ankle fractures in patients aged over 60 years. Health Technology Assessment. 2016 Oct;20(75):1-158
  12. 12. Oliveira PR, Carvalho VC, da Silva Felix C, de Paula AP, Santos-Silva J, Lima AL. The incidence and microbiological profile of surgical site infections following internal fixation of closed and open fractures. Revista Brasileira de Ortopedia. 2016 Feb 2;51(4):396-399
  13. 13. Poultsides LA, Liaropoulos LL, Malizos KN. The socioeconomic impact of musculoskeletal infections. The Journal of Bone and Joint Surgery. American Volume. 2010;92:e13
  14. 14. Gristina AG, Naylor P, Myrvik Q. Infections from biomaterials and implants: A race for the surface. Medical Progress through Technology. 1988;14(3-4):205-224
  15. 15. Gristina AG, Shibata Y, Giridhar G, Kreger A, Myrvik QN. The glycocalyx, biofilm, microbes, and resistant infection. Seminars in Arthroplasty. 1994;5(4):160-170
  16. 16. Dastgheyb S, Parvizi J, Shapiro IM, Hickok NJ, Otto M. Effect of biofilms on recalcitrance of staphylococcal joint infection to antibiotic treatment. Journal of Infectious Diseases. 2015;211:641-650
  17. 17. Busscher HJ, van der Mei HC, Subbiahdoss G, Jutte PC, van den Dungen JJ, Zaat SA, et al. Biomaterial-associated infection: Locating the finish line in the race for the surface. Science Translational Medicine. 2012;4(153):153rv10
  18. 18. Romanò CL, Scarponi S, Gallazzi E, Romanò D, Drago L. Antibacterial coating of implants in orthopaedics and trauma: A classification proposal in an evolving panorama. Journal of Orthopaedic Surgery and Research. 2015;10:157
  19. 19. Moriarty TF, Grainger DW, Richards RG. Challenges in linking preclinical anti-microbial research strategies with clinical outcomes for device-associated infections. European Cells & Materials. 2014;28:112-128
  20. 20. Leach JB, Schmidt CE. Hyaluronan. Encyclopedia of Biomaterials and Biomedical Engineering. New York: Marcel Dekker; 2004. pp. 779-789
  21. 21. Liao YH, Jones SA, Forbes B, Martin GP, Brown MB. Hyaluronan: Pharmaceutical characterization and drug delivery. Drug Delivery. 2005;12:327-342
  22. 22. Volpi N, Schiller J, Stern R, Solt_es L. Role, metabolism, chemical modifications and applications of hyaluronan. Current Medicinal Chemistry. 2009;16:1718-1745
  23. 23. Ardizzoni A, Neglia RG, Baschieri MC, Cermelli C, Caratozzolo M, Righi E, et al. Influence of hyaluronic acid on bacterial and fungal species, including clinically relevant opportunistic pathogens. Journal of Materials Science. Materials in Medicine. 2011;22:2329-2338
  24. 24. Pitarresi G, Palumbo FS, Calascibetta F, Fiorica C, Di Stefano M, Giammona G. Medicated hydrogels of hyaluronic acid derivatives for use in orthopedic field. International Journal of Pharmaceutics. 2013 Jun 5;449(1-2):84-94. DOI: 10.1016/j.ijpharm.2013.03.059. Epub 2013 Apr 12
  25. 25. Laurencin C, Lane JM. Poly (lactic acid) and poly (glycolic acid): Orthopedic surgery applications. In: Brighton C, Friedlaender G, Lane JM, editors. Bone Formation and Repair, Rosemont, Am. Acad. Orthop. Surg. 1994. pp. 325-339
  26. 26. Pavesio A, Renier D, Cassinelli C, Morra M. Anti-adhesive surfaces through hyaluronan coatings. Medical Device Technology. 1997 Sep;8(7):20-21 24-7
  27. 27. Morra M, Cassineli C. Non-fouling properties of polysaccharide-coated surfaces. Journal of Biomaterials Science. Polymer Edition. 1999;10(10):1107-1124
  28. 28. Cassinelli C, Morra M, Pavesio A, Renier D. Evaluation of interfacial properties of hyaluronan coated poly(methylmethacrylate) intraocular lenses. Journal of Biomaterials Science. Polymer Edition. 2000;11(9):961-977
  29. 29. Kadry AA, Fouda SI, Shibl AM, Abu El-Asrar AA. Impact of slime dispersants and anti-adhesives on in vitro biofilm formation of Staphylococcus Epidermidis on intraocular lenses and on antibiotic activities. The Journal of Antimicrobial Chemotherapy. 2009 Mar;63(3):480-484
  30. 30. Drago L, Cappelletti L, De Vecchi E, Pignataro L, Torretta S, Mattina R. Antiadhesive and antibiofilm activity of hyaluronic acid against bacteria responsible for respiratory tract infections. APMIS. 2014 Oct;122(10):1013-1019
  31. 31. Marcuzzo AV, Tofanelli M, Boscolo Nata F, Gatto A, Tirelli G. Hyaluronate effect on bacterial biofilm in ENT district infections: A review. APMIS. 2017 Sep;125(9):763-772
  32. 32. Pirnazar P, Wolinsky L, Nachnani S, Haake S, Pilloni A, Bernard GW. Bacteriostatic effects of hyaluronic acid. Journal of Periodontology. 1999;70:370-374
  33. 33. Carlson GA, Dragoo JL, Samimi B, Bruckner DA, Bernard GW, Hedrick M, Benhaim P. Bacteriostatic properties of biomatrices against common orthopaedic pathogens. Biochemical and Biophysical Research Communications. 2004 Aug 20;321(2):472-478
  34. 34. Radaeva IF, Kostina GA, Il'ina SG, Kostyleva RN. Antimicrobial activity of hyaluronic acid. Zhurnal Mikrobiologii, Epidemiologii, i Immunobiologii. Jan-Feb 2001;(1):74-75
  35. 35. Harris LG, Richards RG. Staphylococcus aureus adhesion to different treated titanium surfaces. Journal of Materials Science. Materials in Medicine. 2004 Apr;15(4):311-314
  36. 36. Junter GA, Thébault P, Lebrun L. Polysaccharide-based antibiofilm surfaces. Acta Biomaterialia. 2016 Jan;30:13-25
  37. 37. Romanò CL, De Vecchi E, Bortolin M, Morelli I, Drago L. Hyaluronic acid and its composites as a local antimicrobial/antiadhesive barrier. Journal of Bone and Joint Infection. 2017;2(1):63-72
  38. 38. Torretta S, Marchisio P, Rinaldi V, Gaffuri M, Pascariello C, Drago L, Baggi E, Pignataro L. Topical administration of hyaluronic acid in children with recurrent or chronic middle ear inflammations. International Journal of Immunopathology and Pharmacology. 2016 Sep;29(3):438-442
  39. 39. Damiano R, Cicione A. The role of sodium hyaluronate and sodium chondroitin sulphate in the management of bladder disease. Therapeutic Advances in Urology. 2011 Oct;3(5):223-232
  40. 40. Constantinides C, Manousakas T, Nikolopoulos P, Stanitsas A, Haritopoulos K, Giannopoulos A. Prevention of recurrent bacterial cystitis by intravesical administration of hyaluronic acid: A pilot study. BJU International. 2004;93(9):1262-1266
  41. 41. Shao Y, Shen ZJ, Rui WB, Zhou WL. Intravesical instillation of hyaluronic acid prolonged the effect of bladder hydrodistention in patients with severe interstitial cystitis. Urology. 2010;75(3):547-550
  42. 42. Lipovac M, Kurz C, Reithmayr F, Verhoeven HC, Huber JC, Imhof M. Prevention of recurrent bacterial urinary tract infections by intravesical instillation of hyaluronic acid. International Journal of Gynaecology and Obstetrics. 2007;96:192-195
  43. 43. Damiano R, Quarto G, Bava I, Ucciero G, Palumbo MI, Autorino R, et al. Prevention of recurrent urinary tract infections by intravesical administration of hyaluronic acid and chondroitin sulphate: A placebo-controlled randomised trial. European Urology. 2011;59:645-651
  44. 44. Ciani O, Arendsen E, Romancik M, Lunik R, Costantini E, Di Biase M, Morgia G, Fragalà E, Roman T, Bernat M, Guazzoni G, Tarricone R, Lazzeri M. Intravesical administration of combined hyaluronic acid (HA) and chondroitin sulfate (CS) for the treatment of female recurrent urinary tract infections: A European multicentre nested case-control study. BMJ Open. 2016 Mar 31;6(3):e009669
  45. 45. Johannsen A, Tellefsen M, Wikesjö U, Johannsen G. Local delivery of hyaluronan as an adjunct to scaling and root planing in the treatment of chronic periodontitis. Journal of Periodontology. 2009 Sep;80(9):1493-1497
  46. 46. Sapna N, Vandana KL. Evaluation of hyaluronan gel (Gengigel(®) ) as a topical applicant in the treatment of gingivitis. Journal of Investigative and Clinical Dentistry. 2011 Aug;2(3):162-170
  47. 47. Eick S, Renatus A, Heinicke M, Pfister W, Stratul SI, Jentsch H. Hyaluronic acid as an adjunct after scaling and root planing: A prospective randomized clinical trial. Journal of Periodontology. 2013 Jul;84(7):941-949
  48. 48. Drago L, Boot W, Dimas K, Malizos K, Hänsch GM, Stuyck J, Gawlitta D, Romanò CL. Does implant coating with antibacterial-loaded hydrogel reduce bacterial colonization and biofilm formation in vitro ? Clinical Orthopaedics and Related Research. 2014 Nov;472(11):3311-3323
  49. 49. Giammona G, Pitarresi G, Palumbo FS, Romanò CL, Meani E, Cremascoli E. Antibacterial hydrogel and use thereof in orthopedics. 2010. WO 2010/086421 A1.
  50. 50. Pitarresi G, Palumbo FS, Albanese A, Fiorica C, Picone P, Giammona G. Self assembled amphiphilic hyaluronic acid graft copolymers for targeted release of antitumoral drug. Journal of Drug Targeting. 2010;18:264-276
  51. 51. Pitarresi G, Palumbo FS, Fiorica C, Calascibetta F, Di Stefano M, Giammona G. Injectable in situ forming microgels of hyaluronic acid-g-polylactic acid for methylprednisolone release. European Polymer Journal. 2013;49:718-725
  52. 52. Palumbo FS, Pitarresi G, Mandracchia D, Tripodo G, Giammona G. New graft copolymers of hyaluronic acid and polylactic acid: Synthesis and characterization. Carbohydrate Polymers. 2006;66:379-385
  53. 53. Cloutier M, Mantovani D, Rosei F. Antibacterial coatings: Challenges, perspectives, and opportunities. Trends in Biotechnology. 2015 Nov;33(11):637-652
  54. 54. Hynes WL, Walton SL. Hyaluronidases of gram-positive bacteria. FEMS Microbiology Letters. 2000;183:201-207
  55. 55. Giavaresi G, Meani E, Sartori M, Ferrari A, Bellini D, Sacchetta AC, Meraner J, Sambri A, Vocale C, Sambri V, Fini M, Romanò CL. Efficacy of antibacterial-loaded coating in an in vivo model of acutely highly contaminated implant. International Orthopaedics. 2014 Jul;38(7):1505-1512
  56. 56. Boot W, Vogely HC, Nikkels PGJ, Pouran B, van Rijen M, Dhert WJA, Gawlitta D. Local prophylaxis of implant-related infections using a hydrogel as carrier. European Cells and Materials. 2015;30(2):19
  57. 57. Boot W, Gawlitta D, Nikkels PGJ, Pouran B, van Rijen MHP, Dhert WJA, Vogely HC. Hyaluronic acid-based hydrogel coating does not affect bone apposition at the implant surface in a rabbit model. Clinical Orthopaedics and Related Research. 2017 Jul;475(7):1911-1919
  58. 58. Lovati AB, Drago L, Bottagisio M, Bongio M, Ferrario M, Perego S, Sansoni V, De Vecchi E, Romanò CL. Systemic and local administration of antimicrobial and cell therapies to prevent methicillin-resistant Staphylococcus epidermidis-induced femoral nonunions in a rat model. Mediators of Inflammation. 2016;2016:9595706. DOI: 10.1155/2016/9595706
  59. 59. Malizos K, Scarponi S, Simon K, Blauth M, Romanò C. Clinical results of an anti-bacterial hydrogel coating of implants: A multi-centre, prospective, comparative study. Bone & Joint Journal. 2015, 2015;97-B(16):138
  60. 60. Romanò CL, Malizos K, Capuano N, Mezzoprete R, D’Arienzo M, Van Der Straeten C, Scarponi S, Drago L. Does an antibiotic-loaded hydrogel coating reduce early post-surgical infection after joint arthroplasty? Journal of Bone and Joint Infection. 2016;1:34-41
  61. 61. Logoluso N, Malizos K, Blauth M, Danita A, Simon K, Romanò C. Anti-bacterial hydrogel coating of osteosynthesis implants: Early clinical results from a multi-center prospective trial. European Cells and Materials. 2015;30(2):35
  62. 62. Malizos K, Blauth M, Danita A, Capuano N, Mezzoprete R, Logoluso N, Drago L, Romanò CL. Fast-resorbable antibiotic-loaded hydrogel coating to reduce post-surgical infection after internal osteosynthesis: A multicenter randomized controlled trial. Journal of Orthopaedics and Traumatology. 2017 Jun;18(2):159-169. DOI: 10.1007/s10195-017-0442-2
  63. 63. Gallazzi E, Capuano N, Scarponi S, Morelli I, Romanò CL. Does one-stage exchange with antibacterial coating of implants provide similar results to a two-stage procedure for the treatment of peri-prosthetic joint infection? Bone & Joint Journal. 2017;99(Suppl. 1):19-19
  64. 64. Parvizi J, Pawasarat IM, Azzam KA, Joshi A, Hansen EN, Bozic KJ. Periprosthetic joint infection: The economic impact of methicillin-resistant infections. The Journal of Arthroplasty. 2010;25(6 Suppl):103-107
  65. 65. Berend KR, Lombardi AV Jr, Morris MJ, Bergeson AG, Adams JB, Sneller MA. Two-stage treatment of hip periprosthetic joint infection is associated with a high rate of infection control but high mortality. Clinical Orthopaedics and Related Research. 2013;471(2):510-518
  66. 66. Kurtz S, Ong K, Lau E, et al. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. The Journal of Bone and Joint Surgery. American Volume. 2007;89(4):780
  67. 67. Kurtz SM, Ong KL, Schmier J, et al. Future clinical and economic impact of revision total hip and knee arthroplasty. The Journal of Bone and Joint Surgery. American Volume. 2007;89(Suppl 3):144
  68. 68. Diaz-Ledezma C, Lichstein PM, Dolan JG, Parvizi J. Diagnosis of periprosthetic joint infection in medicare patients: Multicriteria decision analysis. Clinical Orthopaedics and Related Research. 2014;472(11):3275-3284
  69. 69. Kapadia BH, Johnson AJ, Issa K, Mont MA. Economic evaluation of chlorhexidine cloths on healthcare costs due to surgical site infections following total knee arthroplasty. The Journal of Arthroplasty. 2013 Aug;28(7):1061-1065
  70. 70. Bozic KJ, Ong K, Lau E, et al. Estimating risk in Medicare patients with THA: An electronic risk calculator for periprosthetic joint infection and mortality. Clinical Orthopaedics and Related Research. 2013;471(2):574-583
  71. 71. Eka A, Chen AF. Patient-related medical risk factors for periprosthetic joint infection of the hip and knee. Annals of Translational Medicine. 2015;3(16):233
  72. 72. Barton AJ, Sagers RD, Pitt WG. Bacterial adhesion to orthopedic implant polymers. Journal of Biomedical Materials Research. 1996 Mar;30(3):403-410
  73. 73. Birkenhauer E, Neethirajan S, Weese JS. Collagen and hyaluronan at wound sites influence early polymicrobial biofilm adhesive events. BMC Microbiology. 2014 Jul 16;14:191
  74. 74. Garrido-Gómez J, Arrabal-Polo MA, Girón-Prieto MS, Cabello-Salas J, Torres-Barroso J, Parra-Ruiz J. Descriptive analysis of the economic costs of periprosthetic joint infection of the knee for the public health system of Andalusia. Journal of Arthroplasty. 2013;28(7):1057-1060

Written By

Giammona Gaetano, Giovanna Pitarresi, Palumbo Fabio Salvatore, Maraldi Susanna, Scarponi Sara and Romanò Carlo Luca

Submitted: June 11th, 2017 Reviewed: December 18th, 2017 Published: February 2nd, 2018