Multifunctional load-bearing hybrid hydrogel with combined drug release and photothermal conversion functions

Abstract

The inability of damaged load-bearing cartilage to regenerate and self-repair remains a long-standing challenge in clinical settings. In the past, the use of PVA hydrogels as cartilage replacements has been explored; however, both pristine and annealed PVA are not ideal for load-bearing cartilage applications, and new materials with improved properties are highly desirable. In this work, we developed a novel hybrid hydrogel system consisting of glycerolmodified PVA hydrogel reinforced by a 3D printed PCL-graphene composite scaffold. The composition of the hydrogel within the hybrid material was optimized to achieve high water retention and enhanced stiffness. The hybrid hydrogel formed by reinforcement with a 3D printed PCL-graphene scaffold with optimized architecture demonstrated desirable mechanical properties (stiffness, toughness, and tribological properties) matching those of natural loadbearing cartilage. Our novel hydrogel system has also been designed to provide drug release and on-demand photothermal conversion functions and at the same time offers excellent biocompatibility with low cell adhesion. These promising properties may allow our unique hybrid hydrogel system to be used for potential applications, such as load-bearing cartilage repair/replacement, as well as targeting certain challenging clinical conditions, such as the treatment of severe arthritis.

A Synthetic Hydrogel Composite with the Mechanical Behavior and Durability of Cartilage

“…A,B) Plots of the compressive versus tensile strength and modulus for BC–PVA–PAMPS (this work) and other strong hydrogels (see Table S1 in the Supporting Information for data and references). [ 13–35 ] The multiple data points for BC–PVA–PAMPS are for different compositions. C) BC–PVA–PAMPS easily bears the weight of a 100 lb.…”

Graphene Integrated Hydrogels Based Biomaterials in Photothermal Biomedicine

“…Graphene and its derivatives possess unique physicochemical properties including acceptable biocompatibility, cargo loading capacity, ultrahigh surface area, straightforward bio-functionalization and considerable potential for drug delivery applications [ 111 , 112 , 113 , 114 , 115 ]. GGels have been explored as PTAs in NIR-triggered drug delivery systems [ 116 , 117 , 118 ]. Jiang et al developed a load-bearing system consisting of a glycerol-modified polyvinyl alcohol (PVA) hydrogel reinforced by a 3D printed PCL-graphene scaffold named PG-Pg.…”

“…Under NIR exposure, PG-Pg hydrogels generated heat to induce greater molecular mobility and then promoted drug release by accelerating the transport of both water and drug molecules ( Figure 6 b). The hybrid hydrogel system also allows for minimal protein adsorption and cell adhesion, further demonstrating its excellent potential for load-bearing cartilage applications [ 116 ]. Wang et al fabricated chitosan-modified chemically reduced GO (CrGO) incorporated into a nanogel (CGN) as a thermosensitive nanogel for NIR-triggered drug delivery applications.…”

Additively Manufactured Semiflexible Titanium Lattices as Hydrogel Reinforcement for Biomedical Implants

“…The mechanical properties of hydrogels may also be improved by combining them with one or more reinforcement structures, thereby generating hybrid hydrogels. [22,23] Thanks to the widespread adoption of additive manufacturing (AM) technologies such as fusion deposition modeling, electrospinning, and melt electrowriting, many approaches have focused on the use of biodegradable polymers to reinforce hydrogels. [23,24] Nevertheless, predicting the in vivo degradation half-life of these reinforcement materials from in vitro tests remains challenging.…”

“…[22,23] Thanks to the widespread adoption of additive manufacturing (AM) technologies such as fusion deposition modeling, electrospinning, and melt electrowriting, many approaches have focused on the use of biodegradable polymers to reinforce hydrogels. [23,24] Nevertheless, predicting the in vivo degradation half-life of these reinforcement materials from in vitro tests remains challenging. [25][26][27] Furthermore, the hydrolytic degradation of such polymers releases byproducts that may accumulate in tissues and have shown to cause inflammation [28] and even cytotoxicity.…”