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The field of dermal fillers is evolving rapidly and numerous products are currently on the market. Biodegradable polymers such as polycaprolactone (PCL) have been found to be compatible with several body tissues, and this makes them an ideal material for dermal filling purposes. Hollow PCL spheres were developed by the Council for Scientific and Industrial Research (CSIR) to serve both as an anchor point and a “tissue harbour” for cells. Particles were tested for cytotoxicity and cell adherence using mouse embryo fibroblasts (MEF). MEFs adhered to the particles and no significant toxic effects were observed based on morphology, cell growth, cell viability and cell cycle analysis, suggesting that the particles are suitable candidates for cell delivery systems in an in vivo setting. The objective of providing a “tissue harbour” was however not realized, as cells did not preferentially migrate into the ported particles. In vivo studies were conducted in BALB/c mice into whom particles were introduced at the level of the hypodermis. Mice injected with PCL particles (ported and non-ported; with or without MEFs) showed evidence of local inflammation and increased adipogenesis at the site of injection, as well as a systemic inflammatory response. These effects were also observed in mice that received apparently inert (polystyrene) particles. Ported PCL particles can therefore act as a cell delivery system and through their ability to induce adipogenesis, may also serve as a dermal bulking agent.

Application of supercritical carbon dioxide as an alternative solvent for microformulation of the volatile unstable drug, eucalyptol in polymeric composites.

The aim of the present work is to evaluate the rate and mechanisms of the aerobic biodegradation of biopolymer blends under controlled composting conditions using the CO2 evolution respirometric method. The biopolymer blends of poly (butylene adipate terephthalate) (PBAT) blended with poly (lactic acid) (PLA), and PBAT blended with poly (butylene succinate) (PBS) by melt extrusion, were tested to evaluate the amount of carbon mineralized under home and industrial composting conditions. The changes in the structural, chemical, thermal and morphological characteristics of the biopolymer blends before and after biodegradation were investigated by FT-IR, DSC, TGA, XRD and SEM. Both blends showed higher degradation rates under industrial composting conditions, when compared to home composting conditions. This was confirmed by FT-IR analysis showing an increase in the intensity of hydroxyl and carbonyl absorption bands. SEM revealed that there was microbial colony formation and disintegration on the surfaces of the biopolymer blends. The obtained results suggest that industrial composting conditions are the most suitable for an enhanced biodegradation of the biopolymer blends viz PBAT–PBS and PBAT–PLA.

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