Biocompatible and Thermoresistant Hydrogels Based on Collagen and Chitosan

Abstract

Hydrogels are considered good biomaterials for soft tissue regeneration. In this sense, collagen is the most used raw material to develop hydrogels, due to its high biocompatibility. However, its low mechanical resistance, thermal stability and pH instability have generated the need to look for alternatives to its use. In this sense, the combination of collagen with another raw material (i.e., polysaccharides) can improve the final properties of hydrogels. For this reason, the main objective of this work was the development of hydrogels based on collagen and chitosan. The mechanical, thermal and microstructural properties of the hydrogels formed with different ratios of collagen/chitosan (100/0, 75/25, 50/50, 25/75 and 0/100) were evaluated after being processed by two variants of a protocol consisting in two stages: a pH change towards pH 7 and a temperature drop towards 4 °C. The main results showed that depending on the protocol, the physicochemical and microstructural properties of the hybrid hydrogels were similar to the unitary system depending on the stage carried out in first place, obtaining FTIR peaks with similar intensity or a more porous structure when chitosan was first gelled, instead of collagen. As a conclusion, the synergy between collagen and chitosan improved the properties of the hydrogels, showing good thermomechanical properties and cell viability to be used as potential biomaterials for Tissue Engineering.

Novel Trends in Hydrogel Development for Biomedical Applications: A Review

“…Moreover, in vivo experiment results confirm the ability of CTS-based hydrogels to accelerate tissue regeneration to reduce inflammation and facilitate wound healing [ 102 , 103 ]. Current trends in CTS-based hydrogels for biomedical applications focus on the improvement of CTS performance and properties, from cross-linking strategies [ 99 , 100 , 101 , 188 ] to blending [ 189 , 190 , 191 ] and functionalization of CTS structure [ 192 , 193 ].…”

Chitosan-Based Biomaterials: Insights into Chemistry, Properties, Devices, and Their Biomedical Applications

“…Proteins such as collagen and its hydrolyzed product gelatin [ 168 ] and elastin [ 169 ] have been blended with CHT for hydrogel production since they are particularly suited for tissue regeneration, fulfilling two fundamental requisites: favorable interactions with cells (i.e., adhesion) and cytocompatibility [ 170 ]. However, proteins do not have a polyanionic character as featured by some polysaccharides, and different non-covalent interactions are brought into play in the hydrogel formation, resulting in limited mechanical properties and stability.…”

The Use of Hydrogels for the Treatment of Bone Osteosarcoma via Localized Drug-Delivery and Tissue Regeneration: A Narrative Review

“…Hydrogels are polymeric hydrophilic structures that are capable of absorbing up to thousands of times their dry weight in water without losing their chemical or structural properties [ 45 , 46 ]. Hydrogels are physical gels when the internal networks are connected through molecular interactions or secondary forces, including hydrogen bonding, hydrophobic forces, or ionic forces [ 45 ].…”

“…Hydrogels are physical gels when the internal networks are connected through molecular interactions or secondary forces, including hydrogen bonding, hydrophobic forces, or ionic forces [ 45 ]. Chemical hydrogels have permanent physical bonds since they contain covalently crosslinked internal networks [ 46 ]. Chemical hydrogels are generated by transforming hydrophobic polymers into hydrophilic polymers and crosslinking them to form a network [ 45 ].…”

“…Interestingly, physical hydrogels are less stable due to their dependence on external stimuli such as pH, temperature, and ionic strength. On the contrary, chemical hydrogels are less dependent on external stimuli and have a tendency for greater mechanical resistance [ 46 ]. Finally, the swelling of hydrogels reaches a limit once the cohesive and osmotic forces reach equilibrium [ 47 , 48 ].…”