Use of Chemically Modified Chitosan and Other Natural-Origin Polymers in Tissue Engineering and Drug Delivery

Gelatin is a costless polypeptide material of natural origin, able to form hydrogels that are potentially useful in biomaterial scaffold design for drug delivery, cell cultures, and tissue engineering. However, gelatin hydrogels are unstable at physiological conditions, losing their features only after a few minutes at 37 °C. Accordingly, treatments to address this issue are of great interest. In the present work, we propose for the first time the use of bi- and trifunctional tetrazoles, most of them unknown to date, for photoinduced gelatin cross-linking towards the production of physiologically stable hydrogels. Indeed, after UV-B irradiation, aryl tetrazoles generate a nitrilimine intermediate that is reactive towards different functionalities, some of them constitutively present in the amino acid side chains of gelatin. The efficacy of the treatment strictly depends on the structure of the cross-linking agent used, and substantial improved stability was observed by switching from bifunctional to trifunctional cross-linkers.

Download Full-text

Recent Advances in Chemically-Modified and Hybrid Carrageenan-Based Platforms for Drug Delivery, Wound Healing, and Tissue Engineering

Polymers ◽

10.3390/polym13111744 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1744

Author(s):

Hamidreza Mokhtari ◽

Shima Tavakoli ◽

Fereshteh Safarpour ◽

Mahshid Kharaziha ◽

Hamid Reza Bakhsheshi-Rad ◽

...

Keyword(s):

Drug Delivery ◽

Tissue Engineering ◽

Wound Healing ◽

Polymer Networks ◽

Three Dimensional ◽

Biological Properties ◽

Chemically Modified ◽

Ionic Crosslinking ◽

Crosslinking Process ◽

Recent Advances

Recently, many studies have focused on carrageenan-based hydrogels for biomedical applications thanks to their intrinsic properties, including biodegradability, biocompatibility, resembling native glycosaminoglycans, antioxidants, antitumor, immunomodulatory, and anticoagulant properties. They can easily change to three-dimensional hydrogels using a simple ionic crosslinking process. However, there are some limitations, including the uncontrollable exchange of ions and the formation of a brittle hydrogel, which can be overcome via simple chemical modifications of polymer networks to form chemically crosslinked hydrogels with significant mechanical properties and a controlled degradation rate. Additionally, the incorporation of various types of nanoparticles and polymer networks into carrageenan hydrogels has resulted in the formation of hybrid platforms with significant mechanical, chemical and biological properties, making them suitable biomaterials for drug delivery (DD), tissue engineering (TE), and wound healing applications. Herein, we aim to overview the recent advances in various chemical modification approaches and hybrid carrageenan-based platforms for tissue engineering and drug delivery applications.

Download Full-text

Progress on Modified Chitosan Applied in Drug Delivery System

Chinese Journal of Natural Medicines ◽

10.3724/sp.j.1009.2009.00458 ◽

2010 ◽

Vol 7 (6) ◽

pp. 458-464

Author(s):

Xiao-Li WU ◽

Can ZHANG ◽

Qi-Neng PING

Keyword(s):

Drug Delivery ◽

Drug Delivery System ◽

Delivery System ◽

Modified Chitosan

Download Full-text

Scaffolds for Drug Delivery in Tissue Engineering

International Journal of Pharmaceutical Sciences and Nanotechnology ◽

10.37285/ijpsn.2008.1.2.1 ◽

2008 ◽

Vol 1 (2) ◽

pp. 113-123 ◽

Cited By ~ 2

Author(s):

Vikas V. Gaikwad ◽

Abasaheb B. Patil ◽

Madhuri V. Gaikwad

Keyword(s):

Drug Delivery ◽

Tissue Engineering ◽

Heart Diseases ◽

Cartilage Regeneration ◽

Tissue Growth ◽

The Body ◽

Patient Specific ◽

In Situ Gel ◽

Heart Muscle Cells

Scaffolds are used for drug delivery in tissue engineering as this system is a highly porous structure to allow tissue growth. Although several tissues in the body can regenerate, other tissue such as heart muscles and nerves lack regeneration in adults. However, these can be regenerated by supplying the cells generated using tissue engineering from outside. For instance, in many heart diseases, there is need for heart valve transplantation and unfortunately, within 10 years of initial valve replacement, 50–60% of patients will experience prosthesis associated problems requiring reoperation. This could be avoided by transplantation of heart muscle cells that can regenerate. Delivery of these cells to the respective tissues is not an easy task and this could be done with the help of scaffolds. In situ gel forming scaffolds can also be used for the bone and cartilage regeneration. They can be injected anywhere and can take the shape of a tissue defect, avoiding the need for patient specific scaffold prefabrication and they also have other advantages. Scaffolds are prepared by biodegradable material that result in minimal immune and inflammatory response. Some of the very important issues regarding scaffolds as drug delivery systems is reviewed in this article.

Download Full-text

Hydrogels as Antibacterial Biomaterials

Current Pharmaceutical Design ◽

10.2174/1381612824666180213122953 ◽

2018 ◽

Vol 24 (8) ◽

pp. 843-854 ◽

Cited By ~ 6

Author(s):

Weiguo Xu ◽

Shujun Dong ◽

Yuping Han ◽

Shuqiang Li ◽

Yang Liu

Keyword(s):

Mechanical Properties ◽

Drug Delivery ◽

Tissue Engineering ◽

Water Content ◽

Oxygen Permeability ◽

Structural Diversity ◽

High Water ◽

Clinical Applications ◽

High Water Content ◽

Biomedical Field

Hydrogels, as a class of materials for tissue engineering and drug delivery, have high water content and solid-like mechanical properties. Currently, hydrogels with an antibacterial function are a research hotspot in biomedical field. Many advanced antibacterial hydrogels have been developed, each possessing unique qualities, namely high water swellability, high oxygen permeability, improved biocompatibility, ease of loading and releasing drugs and structural diversity. In this article, an overview is provided on the preparation and applications of various antibacterial hydrogels. Furthermore, the prospects in biomedical researches and clinical applications are predicted.

Download Full-text