There are several sources from which hydroxyapatite (HAp) can be obtained and may be broadly categorized as synthetic or biogenic. Elevated interest in recent times has pushed for the development of several procedures for extracting HAp from biogenic wastes due to their excellent composition and morphology resemblance to the human calcified tissue (B-type carbonated HAp). Notable biogenic sources reported for HAp extraction span bovine bones, fish scales, corals, eggshells, and snails among other calcium-rich sources. However, most of the synthetic methods are laborious and therefore result in high production costs. In this chapter, we discuss the synthesis of B-type carbonate substituted HAp from an untapped biogenic source, Achatina achatina shells, using a simple precipitation method and a controlled heat-treatment method. This unique treatment method affected the substitution resulting in different crystallographic parameters and revealed a novel material for bone implants and enamel applications.
Part of the book: Biomaterials
Traditional herbal medical practices continue to be part of the healthcare needs of the world especially residents of sub-Sahara Africa (sSA). However, the mechanism of action of the plant metabolites to elicit their potency continue to be a mystery due to the lack of standardized methods. The mechanism of plant bioactive compounds to cause cell death is gradually being linked to membrane polarization and depolarization behaviour. The current work seeks to probe the electrochemical response of model cells using bioactive compounds captured in bio-zeolites or membrane mimetics. The voltage and current fluctuations emanating from such studies will establish a correlation between cell death and membrane depolarization. It will be a useful biological interface sensing material with the potential to identify plant metabolites that can selectively detect and destroy diseased cells. Several model membranes have already been developed for biomedical applications and this new paradigm will elevate the usefulness of these model systems. The concept was investigated using extracts from Dioclea reflexa (DR) hook which belongs to the leguminous family. There are certain class of compounds in Dioclea reflexa (DR) that have clinical usefulness in both temperate and tropical regions, however the identity of the bioactive compounds responsible for inducing cell death continue to be a major challenge.
Part of the book: Biosensors