Synthesis and properties of novel polyvinyl alcohol-lactic acid gels

Hydrogels: An overview of its classifications, properties, and applications

The review paper starts with the introduction to hydrogels along with broad literature survey covering different modes of synthesis including high energy radiation methods. After that, paper covered broad classification of the hydrogels depending upon the basis of their source of origin, method of synthesis, type of cross-linking present and ionic charges on bound groups. Another advanced category response triggered hydrogels, which includes pH, temperature, electro, and light and substrate responsive hydrogels was also studied. Presented paper summarises chemical structure, properties, and synthesis of different kinds of hydrogels. Main focus was given to the preparation super absorbents such as: Semi-interpenetrating networks (semi-IPNs), Interpenetrating networks (IPNs) and cross-linked binary graft copolymers (BGCPs). The weak mechanical properties and easy degradation limit the uses of bio-based -hydrogels in biomedical field. Their properties can be improved through different chemical and physical methods. These methods were also discussed in the current research paper. Also, it includes development of hydrogels as controlled drug delivery devices, as implants and biomaterials to replace malfunctioned body parts along with their use in several other applications listed in the literature. Literature survey on the application of hydrogels in different fields like biomedical, nano-biotechnology, tissue engineering, drug delivery and agriculture was also carried out.

Plasticized poly(vinylalcohol) and poly(vinylpyrrolidone) based patches with tunable mechanical properties for cardiac tissue engineering applications

Polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) are the two most investigated biopolymers for various tissue engineering applications. However, their poor tensile strength renders them unsuitable for cardiac tissue engineering (CTE). In this study, we developed and evaluated PVA-PVP-based patches, plasticized with glycerol or propylene glycol (0.1%-0.4%; v:v), for their application in CTE. The cardiac patches were evaluated for their physico-chemical (weight, thickness, folding endurance, FT-IR, and swelling behavior) and mechanical properties. The optimized patches were characterized for their ability to support in vitro attachment, viability, proliferation, and beating behavior of neonatal mouse cardiomyocytes (CMs). In vivo evaluation of the cardiac patches was done under the subcutaneous skin pouch and heart of rat models. Results showed that the optimized molar ratio of PVA:PVP with plasticizers (0.3%; v-v) resulted in cardiac patches, which were dry at room temperature and had desirable folding endurance of at least 300, a tensile strength of 6-23 MPa and, percentage elongation at break of more than 250%. Upon contact with phosphate-buffered saline, these PVA-PVP patches formed hydrogel patches having the tensile strength of 1.3-3.0 MPa. The patches supported the attachment, viability, and proliferation of primary neonatal mouse CMs and were nonirritant and noncorrosive to cardiac cells. In vivo transplantation of cardiac patches into a subcutaneous pouch and on the heart of rat models revealed them to be biodegradable, biocompatible, and safe for use in CTE applications.

PLA architectures: the role of branching

Biobased and biodegradable polymers have become more and more interesting in view of waste management and crude oil depletion.