Biomaterial-Based Hydrogels for Chronic Wound Healing: A Comparative Review of Natural Polymers

Chronic wounds have been both a problem and a challenge to both patients and healthcare systems all over the world. Standard treatments like gauze dressings are generally not adequate to promote the active tissue regeneration that chronic wounds lack. Hydrogels based on biomaterials have appeared as a promising alternative treatment that provides a moist environment for healing, mechanical support, and the possibility of being modified to include therapeutic agents. This review assesses and compares four main natural biomaterials used in the formulation of hydrogels for chronic wound healing, examining their structural characteristics, mechanisms of action, and evidence for effectiveness across different types of chronic wounds. The results indicate that no single biomaterial is superior for all chronic wound types; instead, material selection may be guided by properties suited to specific wound traits. Alginate's fluid-absorption capacity suggests utility for highly exudative wounds; chitosan's antimicrobial properties suggest utility for infection-prone wounds; collagen's cell-adhesion properties suggest utility for structurally damaged wounds; and hyaluronic acid's moisture-retention properties suggest utility where long-term moisture retention and regenerative support are needed. These associations are based on mechanistic and preclinical evidence rather than direct comparative clinical trials.

Nevertheless, evidence for these materials is still uneven, with a shortage of large-scale randomized controlled trials and a strong dependence on data from animal studies for composite systems. This review points out these gaps in the evidence. It sets out priorities for future research, such as conducting standardized clinical trials, designing studies that are specific to the type of wound, and further developing composite biomaterial systems, to help create more effective and evidence-based hydrogel treatments for the management of chronic wounds.