Nanostructured Dense Collagen‐Polyester Composite Hydrogels as Amphiphilic Platforms for Drug Delivery

Abstract

Associating collagen with biodegradable hydrophobic polyesters constitutes a promising method for the design of medicated biomaterials. Current collagen‐polyester composite hydrogels consisting of pre‐formed polymeric particles encapsulated within a low concentrated collagen hydrogel suffer from poor physical properties and low drug loading. Herein, an amphiphilic composite platform associating dense collagen hydrogels and up to 50 wt% polyesters with different hydrophobicity and chain length is developed. An original method of fabrication is disclosed based on in situ nanoprecipitation of polyesters impregnated in a pre‐formed 3D dense collagen network. Composites made of poly(lactic‐co‐glycolic acid) (PLGA) and poly(lactic acid) (PLA) but not polycaprolactone (PCL) exhibit improved mechanical properties compared to those of pure collagen dense hydrogels while keeping a high degree of hydration. Release kinetics of spironolactone, a lipophilic steroid used as a drug model, can be tuned over one month. No cytotoxicity of the composites is observed on fibroblasts and keratinocytes. Unlike the incorporation of pre‐formed particles, the new process allows for both improved physical properties of collagen hydrogels and controlled drug delivery. The ease of fabrication, wide range of accessible compositions, and positive preliminary safety evaluations of these collagen‐polyesters will favor their translation into clinics in wide areas such as drug delivery and tissue engineering.

Hierarchically Assembled Type I Collagen Fibres as Biomimetic Building Blocks of Biomedical Membranes

“…In contrast to synthetic polymers, customisation of biomimetic systems into fibrous materials presents challenges with regards to fibre spinning compatibility, given the limited solubility in organic solvents, the long-range nanoscale organisation and the shape instability of resulting fibres in aqueous environments [ 7 ]. While bespoke manufacturing routes have been developed to enable the conversion of biomimetic systems into fibres [ 8 , 9 ], the molecular manipulation of biopolymers derived from the extracellular matrix (ECM) of biological tissues may offer a more time effective approach to ensure the formation of fibres with biomimetic features from the molecular up to the macroscopic scale, as well scalability for industrial uptake [ 10 , 11 ].…”

Stimuli-Responsive Toughening of Hydrogels

“…[2][3] Bearing high level of water contents, hydrogels serve as ideal candidates for bio-engineering applications as they share versatile similarities with human tissues. [4][5] Moreover, their ability to be programmed concerning one or various given stimuli considerably broadens their application perspectives. Typical stimuli involve temperature, pH, humidity, light, specific ions or molecules, electrical field, magnetic field, solvent, and ionic strength.…”

Effect of Mammalian Tissue Source on the Molecular and Macroscopic Characteristics of UV-Cured Type I Collagen Hydrogel Networks

“…In light of its major role in wound healing and tissue remodelling, collagen has therefore been successfully applied in wound dressings [3,4], guided bone regeneration membranes [5], tendon repair scaffolds [6], pelvic reconstruction meshes [7,8], as well as tracheal [9,10] and corneal [11] implants. Consequently, multiple design strategies, including blending with synthetic polymers [12], fibre spinning [13], and covalent crosslinking [14], have been developed for a range of collagen raw materials generating varying preclinical success. The selection of the tissue source for the extraction of the collagen raw material has increasingly been identified as a key aspect to ensure reproducibility, scalable development, and clinical translation of new medical device prototypes.…”