Ziyad S. Haidar

By Ziyad S. Haidar

Leukocyte and platelet-rich fibrin (L-PRF) is a 3-D autogenous biomaterial derived via simple and rapid centrifugation of whole blood patient samples, in the absence of anti-coagulants, bovine thrombin, additives or any gelifying agents. A relatively new “revolutionary” step in second generation platelet concentrate-based therapeutics, clinical effectiveness of L-PRF remains highly-debatable, whether due to preparation protocol variability, limited evidence-based clinical literature and/or inadequate understanding of its biocomponents. This critical review provides an update on the application of L-PRF during oral surgery procedures, in human Randomized and Controlled Clinical Trials only (up to February 2016). Accordingly, autologous L-PRF is often associated with early bone formation and maturation; accelerated soft-tissue healing; and reduced post-surgical pain and discomfort. L-PRF is a simple, malleable and safe biomaterial suitable for use in oral surgery. An innovative tool in Regenerative Dentistry, L-PRF is a strong alternative and possibly cost-effective biomaterial for oral-tissue regeneration. Preparation protocols require revision and standardization. Furthermore, a good analysis of its rheological properties, biocomponents and their bioactive function would enhance the validity, comprehension and therapeutic potential of the reported findings or observations; a step closer towards a new era of “super” dental biomaterials and bioscaffolds.

Part of the book: Bone Grafting

By Ziyad S. Haidar

Saliva has a critical role in the maintenance of oral, dental and general health and well-being. Alteration(s) in the amount/quantity and/or quality of secreted saliva may induce the development of several oro-dental variations, thereby negatively-impacting overall quality of life. Diverse factors may affect the process of saliva production and quantity/quality of secretion, including medications, systemic or local pathologies and/or reversible/irreversible damage. Indeed, chemo- and/or radio-therapy, particularly, in cases of head and neck cancer, for example, are well-documented to induce serious damage and dysfunction to the radio-sensitive salivary gland tissue, resulting in hypo-salivation, xerostomia (dry mouth) as well as numerous other adverse intra−/extra-oral, medical and quality-of-life issues. Although a single governing mechanism of radiation-induced salivary gland tissue damage and dysfunction has not been yet elucidated, the potential for a synergy in radio-protection (mainly, and possible -reparation) via a combinatorial approach of mechanistically distinct strategies, has been suggested and explored over the years. This is, undoubtfully, in parallel to the ongoing efforts in improving the precision, safety and efficacy of radiotherapy protocols/outcomes, as well as in developing new technological and pharmaceutical alternatives, topics covered in this chapter.

Part of the book: Biomechanics and Functional Tissue Engineering

By Sebastián E. Pérez and Ziyad S. Haidar

Part of the book: Biomechanics and Functional Tissue Engineering

By Ziyad S. Haidar

Part of the book: Biomimetics

By Ziyad S. Haidar

This chapter introduces the scope of the book—bioMIMETICS can be described as an innovative form of technology that imitates (or mimics) nature in order to improve human lives via creating desirable solutions. It is the study of nature and natural phenomena, principles, and underlying mechanisms, to obtain bio-inspired that may benefit various applied scientific and technological disciplines. Smart/Intelligent nano-bioMaterials for Tissue Engineering and Regenerative Medicine are a fine example. Yet, biomimicry can go above and beyond the simplistic inspiration and use of natural properties as the basis for innovation of new products. It bridges the gap between the lab and the industry, via the intra-disciplinary design and formulation of functional solutions combining knowledge, methods, techniques, and advances in the fields of chemistry, biology, architecture, engineering, medicine, pharmaceutics, dentistry, and biomedical engineering. Three-Dimensional Printing, Hybrid nanoCoatings, and Stimuli-sensitive and -responsive Cell/Drug Delivery Systems, and Robotics are some of the topics covered in this new book. In this first chapter, a general overview of bio-inspired materials, technologies, and strategies, collectively known as “bioMiMETICS,” is presented to bridge the gap between the laboratory “bench-top” and translational application, particularly, the clinic or “bed-/chair-side,” with a focus on “REGENERATIVE DENTISTRY” and the “CRANIO-MAXILLO-FACIAL bio-COMPLEX.”

Part of the book: Biomimetics

By Ziyad S. Haidar

Metastasis, the spread of cancer cells from the primary tumor to the surrounding tissues and to distant organs, is one (and perhaps the primary) of the major causes of cancer-related death (or cancer morbidity and mortality). Indeed, it is estimated that metastasis is responsible for about 90% of cancer deaths. The major factors contributing to the metastasis of cancer cells are epithelial-mesenchymal transition (EMT) and cancer stem cells (CSCs). Herein, the cancer cells must detach from the primary tumor, intravasate into the circulatory and lymphatic systems, evade immune attack, extravasate at distant capillary beds, and invade and proliferate in distant organs. Accruing evidence suggests that the malfunction of epigenetic regulation in the functioning of a gene is directly related to the generation of tumors and cancer. Henceforth, the potential and capacity to change or re-program the epigenetic landscape within the epigenome of cancer is possibly the most promising and pursued targeted therapy, nowadays. Such would lead to reversing drug resistance and so, new therapeutic modalities. Indeed, contemporary oncologic pharmaco-therapy for cancer has and continues to undergo remarkable changes; especially lately, in terms of the introduction of effective cancer-specific molecular-targeted therapeutic agents. This introductory chapter to the book titled: “DNA Replication – Mechanisms, Epigenetics, and Gene Therapy Applications” discusses DNA and RNA methylation, the mechanisms of histone modification, and presents a variety of epigenetic modifications which can lead to anti-tumor drug resistance. It also explores how targeting epigenetic modifiers can reverse drug resistance.

Part of the book: DNA Replication: Epigenetic Mechanism and Gene Therapy Applications [Working title]