Biopolymer Composites with Sensors for Environmental and Medical Applications

One of the biggest economic and environmental sustainability problems is the over-reliance on petroleum chemicals in polymer production. This paper presents an overview of the current state of knowledge on biopolymers combined with biosensors in terms of properties, compounding methods and applications, with a focus on medical and environmental aspects. Therefore, this article is devoted to environmentally friendly polymer materials. The paper presents an overview of the current state of knowledge on biopolymers combined with biosensors in terms of properties, compounding methods and applications, with a special focus on medical and environmental aspects. The paper presents the current state of knowledge, as well as prospects. The article shows that biopolymers made from renewable raw materials are of great interest in various fields of science and industry. These materials not only replace existing polymers in many applications, but also provide new combinations of properties for new applications. Composite materials based on biopolymers are considered superior to traditional non-biodegradable materials due to their ability to degrade when exposed to environmental factors. The paper highlights the combination of polymers with nanomaterials which allows the preparation of chemical sensors, thus enabling their use in environmental or medical applications due to their biocompatibility and sensitivity. This review focuses on analyzing the state of research in the field of biopolymer-sensor composites.

Biopolymers and Biomaterials for Special Applications within the Context of the Circular Economy

The main challenge of the economy is counteracting the adverse effects of progressive industrialisation on the environment around the world. Economic development that accompanies this trend correlates to production increase in not only consumer articles but also special application articles that are difficult to remanufacture, such as medical supplies. For many researchers, discovering innovative materials for special applications that could become an essential element of circular economy production is important. Measures to reduce the production of industrial materials whose waste is difficult to recycle are more and more apparent to manufacturers, especially when faced with the new financial situation in European Union, as one of its priorities is to implement the principles of circular economy. The purpose of the article is to analyse the current state of research on special-application biomaterials within the context of the circular economy. Empirical analysis is conducted for Poland compared to the rest of the European Union (EU) within the time-frame of 2014-2020, which is the most recent financial timeframe of the EU. The submitted studies are based on secondary data obtained mainly from European databases, as well as primary data resulting from the research works at Łukasiewicz Research Network-Institute of Biopolymers and Chemical Fibres.

Toxicological and Sensitization Studies of Novel Vascular Prostheses Made of Bacterial Nanocellulose Modified with Chitosan (MBC) for Application as the Tissue-Engineered Blood Vessels

Background

Tissue-engineered blood vessels (TEBV) represent an attractive approach for overcoming reconstructive problems associated with vascular diseases in humankind by providing small caliber vascular grafts. The study evaluates biocompatibility and bioaffinity of vascular prostheses made from chitosan-modified bacterial cellulose (MBC) as potential scaffolds for TEBV.

Methods

During the study, acute oral toxicity, up-and-down procedure (UDP), OECD test No. 425 on 10 Imp:WIST rats, intradermal reactivity on three Imp:BN albino rabbits, and sensitization on 15 Imp:DH guinea pigs were performed. The local effects were determined 1 month after intramuscular implantation of prostheses in 30 Imp:WIST rats. Histopathological and pathomorphological studies were conducted following complete removal of implants with peri-implant tissue.

Results

There were no signs of toxicity; the median lethal oral dose (LD50) was greater than 2 g/kg body weight for the rats. No allergic reactions were observed in the case of the guinea pig maximization test. Vascular grafts did not induce significant reactive changes in intradermal reactivity test (Main Irritation Index value 0.03) and do not induce inflammatory changes or hyperplasia of the muscle tissue surrounding the implant. Histopathological examination revealed ingrown vascular-connective bands.

Conclusions

Tubes made of MBC offer strong potential for use in future TEBV programs for vascular surgery.

Lay Summary

Currently, the number of autologous grafts for coronary artery disease and for peripheral artery disease is limited. Particularly materials that will have contact with blood must comply with certain requirements such as mechanical strength, biocompatibility, and no potential to evoke adverse reactions. Bacterial nanocellulose modified with chitosan (MBC) due to its mechanical and biological properties is a promising material for replacing small-diameter vessels grafts. Although previous studies have not shown the toxicity of nanocellulose, we want to check whether medical products based on MBC will be safe when testing in vivo. Thirty Imp:WIST rats and 15 Imp:DH guinea pigs were subject of thorough analysis of potential toxicological and sensitization effect that may develop after applying vascular prostheses made from MBC to living organism. The analysis involved also histopathological and pathomorphological studies following complete removal of implants with peri-implant tissue. The results show that MBC prostheses do not cause any allergic, intradermal reactions and finally, do not display acute toxicity towards the organism in which it is implanted. Moreover, they had not induced inflammatory changes or hyperplasia of the muscle tissue surrounding the implantation sites, thus showing good biocompatibility. Obtained results were discussed with other available studies investigating various aspects of bacterial cellulose or modified bacterial cellulose influence on cells and tissues in both in vitro and in vivo studies. This is the first study analyzing the toxicological and sensitization effect which MBC may evoke and confirm the strong potential for use in future TEBV programs for vascular surgery.

Graphical Abstract