DEVELOPMENT OF A NATURAL POLYMER-BASED HYDROGEL FOR BIOENGINEERED VASCULAR GRAFTS

Introduction

Cardiovascular diseases are a main cause of death globally, and their treatment implies various vascular repairs through different techniques like angioplasty, stent placement in the blocked artery, or bypass surgery. Artificial grafts would significantly reduce the number of non-treated patients, but middle and long-term failures compromise their clinical use.

Methods

Herein, we developed a hydrogel composed of gellan gum, gelatin, and sodium alginate for bioengineered vascular graft production. The vascular grafts were characterized by their swelling, porosity, biodegradability, and cytotoxic profile.

Results

The bioengineered materials were easily assembled due to the thermoresponsive nature of the hydrogel and had a vessel-like structure resembling the native vasculature. These vessels had a very controlled swelling degree, and notably, the hydrogel structure was stable and maintained its morphology. The vascular grafts had a porosity of 82.6 ± 4.3% and exhibited a controlled biodegradation rate with a maximum of 24.2 ± 3.0%. As expected, the natural materials used showed no cytotoxicity toward HUVECs cells since they are natural polymers described as biocompatible.

Conclusions

This developed natural hydrogel showed promising potential to be used to develop bioengineered vascular grafts.

Production of new 3D scaffolds for bone tissue regeneration by rapid prototyping

The incidence of bone disorders, whether due to trauma or pathology, has been trending upward with the aging of the worldwide population. The currently available treatments for bone injuries are rather limited, involving mainly bone grafts and implants. A particularly promising approach for bone regeneration uses rapid prototyping (RP) technologies to produce 3D scaffolds with highly controlled structure and orientation, based on computer-aided design models or medical data. Herein, tricalcium phosphate (TCP)/alginate scaffolds were produced using RP and subsequently their physicochemical, mechanical and biological properties were characterized. The results showed that 60/40 of TCP and alginate formulation was able to match the compression and present a similar Young modulus to that of trabecular bone while presenting an adequate biocompatibility. Moreover, the biomineralization ability, roughness and macro and microporosity of scaffolds allowed cell anchoring and proliferation at their surface, as well as cell migration to its interior, processes that are fundamental for osteointegration and bone regeneration.