RESUMO
The restoration of normal functioning of damaged body tissues is one of the major objectives of tissue engineering. Scaffolds are generally used as artificial supports and as substrates for regenerating new tissues and should closely mimic natural extracellular matrix (ECM). The materials used for fabricating scaffolds must be biocompatible, non-cytotoxic and bioabsorbable/biodegradable. For this application, specifically biopolymers such as PLA, PGA, PTMC, PCL etc. satisfying the above criteria are promising materials. Poly(ε-caprolactone) (PCL) is one such potential candidate which can be blended with other materials forming blends, copolymers and composites with the essential physiochemical and mechanical properties as per the requirement. Nanofibrous scaffolds are fabricated by various techniques such as template synthesis, fiber drawing, phase separation, self-assembly, electrospinning etc. Among which electrospinning is the most popular and versatile technique. It is a clean, simple, tunable and viable technique for fabrication of polymer-based nanofibrous scaffolds. The design and fabrication of electrospun nanofibrous scaffolds are of intense research interest over the recent years. These scaffolds offer a unique architecture at nano-scale with desired porosity for selective movement of small molecules and form a suitable three-dimensional matrix similar to ECM. This review focuses on PCL synthesis, modifications, properties and scaffold fabrication techniques aiming at the targeted tissue engineering applications.
RESUMO
The reverse micellar system of sodium bis(2-ethylhexyl)sulfosuccinate (AOT)/isooctane was used for the extraction and primary purification of beta-galactosidase (EC 3.2.1.23) from the aqueous extract of barley (Hordeum vulgare) for the first time. The process parameters such as the concentration of the surfactant, the volume of the sample injected, and its protein concentration, pH, and ionic strength of the initial aqueous phase for forward extraction, buffer pH, and salt concentration for back extraction are varied to optimize the extraction efficiency. Studies carried out with both phase transfer and injection mode of reverse micellar extraction confirmed the injection mode to be more suitable for beta-galactosidase extraction. The extent of reverse micellar solubilization of proteins increased with an increase in protein concentration of the feed sample. However, back extraction efficiency remained almost constant (13-14.4%), which indicates the selectivity of AOT reverse micelles for a particular protein under given experimental conditions. beta-Galactosidase was extracted with an activity recovery of 98.74% and a degree of purification of 7.2-fold.
