Natural carriers for application in tuberculosis treatment

Tuberculosis remains the leading cause of preventable deaths worldwide and unsuccessful therapy is mainly due to non-compliance with very prolonged treatments, often associated with severe side-effects. Overcoming this problem demands the introduction of drug carriers releasing the antimicrobial agents in a targeted and sustained manner, allowing reduction in frequency and dosing numbers. Nano and microparticles have taken the forefront of this approach, providing the means for the desired improvement of therapeutic schedules. Natural polymers are strong candidates as matrix forming materials, usually exhibiting biocompatibility, biodegradability, low cost and some technological advantages as compared with synthetic counterparts. In this review, natural particulate carriers developed for tuberculosis therapy are presented, mainly focusing on the use of polysaccharides and lipids. Their effectiveness is discussed taking into account their composition. Finally, considerations on the general potential of natural materials for this application, as well as key factors still to be addressed, are discussed

Wound Healing Potential of Formulated Extract from Hibiscus Sabdariffa Calyx

Wound healing agents support the natural healing process, reduce trauma and likelihood of secondary infections and hasten wound closure. The wound healing activities of water in oil cream of the methanol extract of Hibiscus sabdariffa L. (Malvaceae) was evaluated in rats with superficial skin excision wounds. Antibacterial activities against Pseudomonas aeroginosa, Staphylococcus aureus and Echerichia coli were determined. The total flavonoid content, antioxidant properties and thin layer chromatographic fingerprints of the extract were also evaluated. The extract demonstrated antioxidant properties with a total flavonoid content of 12.30±0.09 mg/g. Six reproducible spots were obtained using methanol:water (95:5) as the mobile phase. The extract showed no antimicrobial activity on the selected microorganisms, which are known to infect and retard wound healing. Creams containing H. sabdariffa extract showed significant (P<0.05) and concentration dependent wound healing activities. There was also evidence of synergism with creams containing a combination of gentamicin and H. sabdariffa extract. This study, thus, provides evidence of the wound healing potentials of the formulated extract of the calyces of H. sabdariffa and synergism when co-formulated with gentamicin

Natural fiber biodegradable composites and nanocomposites: A biomedical application

The growing interest for “green” materials for biomedical applications has increased in recent years. This attention was due to researchers, patients, and the medical world searching for several solutions to their challenges, such as the need to replace, repair, or substitute tissues or organs. In this context, recently tissue engineering has been the focus of the development and application of biodegradable polymers obtained from natural sources (vegetable and animal), for example: collagen, chitosan, chitin, starch, gelatin, alginate, and cellulose. These materials represent a valid alternative to replace and substitute petrochemical products in biomedical applications. However, synthetic aliphatic polymers, such as poly(lactic acid) (PLA), poly(glycolides) (PGA), and poly(ε-caprolactone) (PCL) have also attracted wide attention for their biocompatibility and biodegradability in the human body and have been extensively studied and characterized to develop medical devices. This chapter reports on the most relevant results about the use of natural fibers or nanofillers extracted from natural fibers as reinforcement phases for the production of composite materials for biomedical applications. The development of composites and nanocomposites has emerged in the last two decades as an efficient approach to upgrade the functional and structural properties of synthetic and/or natural polymers. In addition, the introduction of nanofillers into biodegradable polymers to produce nanocomposites allows preparing a new class of biodegradable materials with enhanced and tuneable thermal, mechanical, and electrical properties