Acellular biomaterials: an evolving alternative to cell-based therapies

Abstract

Acellular biomaterials can stimulate the local environment to repair tissues without the regulatory and scientific challenges of cell-based therapies. A greater understanding of the mechanisms of such endogenous tissue repair is furthering the design and application of these biomaterials. We discuss recent progress in acellular materials for tissue repair, using cartilage and cardiac tissues as examples of applications with substantial intrinsic hurdles, but where human translation is now occurring.

Fig. 1. The evolving roles of acellular biomaterials in tissue repair

The application of acellular biomaterials ranges from traditional approaches of promoting tissue formation through mechanical support or the delivery of growth factors, to current/ongoing approaches to vascularize and organize tissues, and to emerging techniques that modulate endogenous cellular processes and recruitment.

Fig. 2. Cartilage and cardiac tissues exemplify advances in acellular materials

Tissues damaged through traumatic and disease processes undergo adverse responses if left untreated. (A) In cartilage tissue, small lesions can progress to large areas of joint erosion and be accompanied by pain. Acellular, injectable gels and implantable scaffolds that recruit stem cells may improve tissue repair. In cardiac tissue, myocardial infarction initiates a cascade of events that leads to LV dilatation. (B) Acellular biomaterials can be used to alter the local stress profiles and to deliver therapeutic molecules.