Tough and tunable scaffold-hydrogel composite biomaterial for soft-to-hard musculoskeletal tissue interfaces

Abstract

Tendon inserts into bone via a fibrocartilaginous interface (enthesis) that reduces mechanical strain and tissue failure. Despite this toughening mechanism, tears occur because of acute (overload) or degradative (aging) processes. Surgically fixating torn tendon into bone results in the formation of a scar tissue interface with inferior biomechanical properties. Progress toward enthesis regeneration requires biomaterial approaches to protect cells from high levels of interfacial strain. We report an innovative tissue reinforcement strategy: a stratified scaffold containing osseous and tendinous tissue compartments attached through a continuous polyethylene glycol (PEG) hydrogel interface. Tuning the gelation kinetics of the hydrogel modulates integration with the flanking compartments and yields biomechanical performance advantages. Notably, the hydrogel interface reduces formation of strain concentrations between tissue compartments in conventional stratified biomaterials that can have deleterious biological effects. This design of mechanically robust stratified composite biomaterials may be appropriate for a broad range of tendon and ligament-to-bone insertions.

Growing Pains: The Need for Engineered Platforms to Study Growth Plate Biology

“…Sun Han Chang et al fabricated a continuous triphasic scaffold with three distinct regions for bone, cartilage, and tendon. [ 195 ] The researchers used a freeze‐drying process and a custom mold to generate a continuous triphasic scaffold for tendon‐bone repair in which a compliant PEG hydrogel was incorporated between mechanically dissimilar tendinous and osseous materials. [ 195 ] The researchers illustrated a reduction in strain at the biomaterial interface between these two dissimilar biomaterials by tuning hydrogel fabrication parameters.…”

“…[ 195 ] The researchers used a freeze‐drying process and a custom mold to generate a continuous triphasic scaffold for tendon‐bone repair in which a compliant PEG hydrogel was incorporated between mechanically dissimilar tendinous and osseous materials. [ 195 ] The researchers illustrated a reduction in strain at the biomaterial interface between these two dissimilar biomaterials by tuning hydrogel fabrication parameters. [ 195 ] The design parameters discussed in this article may prove useful to other researchers developing materials for interfacial zones in the musculoskeletal system.…”

“…[ 195 ] The researchers illustrated a reduction in strain at the biomaterial interface between these two dissimilar biomaterials by tuning hydrogel fabrication parameters. [ 195 ] The design parameters discussed in this article may prove useful to other researchers developing materials for interfacial zones in the musculoskeletal system. Further, fabrication techniques that combine tissue engineering constructs for multiple tissue types may be useful for the growth plates given that they are sandwiched between bones.…”

Promising Clinical Applications of Hydrogels Associated With Precise Cancer Treatment: A Review

“…Hydrogels are a type of soft and crosslinked hydrophilic polymer network and can be adapted to meet the requirements of different settings by altering material components and chemical modifying approaches. 1 Due to favorable physicochemical characteristics and high biocompatibility, various hydrogels have been designed and developed for biomedical applications, such as regenerative medicine, 2 , 3 tissue engineering scaffolds, 4 , 5 drug delivery system, 6 , 7 and cancer precision medicine. 8 – 10 In particular, there is an increasing utilization of hydrogels in the diagnosis and treatment of cancers.…”

In Situ Biomimetic Mineralization of Bone-Like Hydroxyapatite in Hydrogel for the Acceleration of Bone Regeneration

“…Currently, surgical intervention by implanting autograft, allograft, or artificial materials at defect areas followed by endogenic osteogenesis is a general strategy for bone regeneration. , Considering the major component of the nano-HAP and organic matrix in bone, several composite/hybrid materials have been prepared to mimic inorganic minerals and organic molecules synchronously for the construction of an osteogenic microenvironment . The mimicking of organic matrix had been achieved using biomimetic hydrogels, such as alginate, chitosan, hyaluronic acid, polyethylene glycol, and gelatin . The unique configurations, tunable physicochemical properties, and excellent biocompatibility of hydrogels significantly promote bone regeneration .…”