Novel Crosslinking Methods to Design Hydrogels

Hydrogels are presently under consideration as matrices for the controlled bioactive molecules delivery particularly proteins and for living cells encapsulation. For these applications, gels must undergo degradation under physiological conditions. This overview summarized and discussed the various physical and chemical crosslinking methods to design hydrogels that are biodegradable. Highly versatile method to prepare hydrogels with good mechanical stability is chemical crosslinking. However, the crosslinker employed can give undesirable reactions with the bioactive substances present in the hydrogel matrix and are often toxic. So, it required to be removed from the gels before application. Physically crosslinked gels can be developed to overcome these adverse effects. Distortion due to variations in environmental conditions like presence of solute particles, ionic strength, pH, temperature and stress are the major disadvantages of reversible gels