Sustainable chitosan-based electrical responsive scaffolds for tissue engineering applications
داربست های پاسخگو الکتریکی مبتنی بر کیتوزان پایدار برای کاربردهای مهندسی بافت-2021
Electroconductive biomaterials have potential in the regeneration of electrically active biological tissues (neural, orthopedic, cardiac). The aim of this study was to develop an electroconductive scaffold using natural and/or sustainable materials. A composite scaffold made of chitosan, a compound of natural origin, and with incorporated with graphitic carbon obtained from cork (natural and sustainable source) as an electroconductive filler, was prepared. Chitosan (Ch) scaffolds with different concentration of pyrolyzed cork (PC) were prepared and fully characterized. An electroconductivity of 5.5 × 10−5 S/cm, i.e. in the range of cardiac tissues, was obtained. FTIR and XPS analysis did not show the presence of chemical bonds between the two components. Despite this, the composite scaffold showed higher thermal stability; moreover, their mechanical strength was significantly higher than for the pure chitosan. The biocompatibility of Ch-PC composite scaffolds has been verified by SH-SY5Y neuroblastoma cell viability assay. This study shows that a sustainable composite made with chitosan and an innovative electroconductive filler has potential application in tissue engineering.
Keywords: Conductive polymers | Chitosan | Tissue engineering | Graphitic carbon | Natural sources
3D-printable conductive materials for tissue engineering and biomedical applications
مواد رسانای قابل چاپ سه بعدی برای مهندسی بافت و کاربردهای زیست پزشکی-2021
Many patients that undergo autografting suffer from donor site morbidity and risk of immune rejection. Tissue engineering is receiving considerable attention as engineered tissues could help overcome the drawbacks of autografts and achieve better performance on tissue repair, replacement and regeneration. Conductivity is one of the desired properties of engineered scaffolds and tissue constructs as bioelectricity plays an important role in the native physiological environment. Hence, conductive materials have been extensively used in the making of biosensors, tissue engineering scaffolds and drug delivery systems to elicit electrically-mediated signals, thus mimicking the natural cellular environment. Conductive polymers, carbon-based materials, and metal nanoparticles are the main categories of conductive materials used. Ionic liquids, especially biocompatible ionic liquids, is currently being explored as a competitive filler composite to greatly improve the conductivity of polymers with little to zero cytotoxicity. The effects of electrical stimulation on cell alignment, migration, proliferation, and differentiation as well as detailed properties of different types of conductive materials are briefly yet succinctly reviewed. Furthermore, 3D printing of conductive scaffolds and hydrogels, and their corresponding biomedical applications are also discussed.
Keywords: Conductive biomaterials | Bioprinting | Tissue engineering | Ionic liquids | Electrical stimulation
Printable alginate/gelatin hydrogel reinforced with carbon nanofibers as electrically conductive scaffolds for tissue engineering
هیدروژل آلژینات/ژلاتین قابل چاپ تقویت شده با نانوالیاف کربن به عنوان داربست های رسانای الکتریکی برای مهندسی بافت-2021
Shortages of organs and damaged tissues for transplantation have prompted improvements in biomaterials within the field of tissue engineering (TE). The rise of hybrid hydrogels as electro-conductive biomaterials offers promise in numerous challenging biomedical applications. In this work, hybrid printable biomaterials comprised of alginate and gelatin hydrogel systems filled with carbon nanofibers (CNFs) were developed to create electroconductive and printable 3-D scaffolds. Importantly, the preparation method allows the formation of hydrogels with homogenously dispersed CNFs. These hybrid composite hydrogels were evaluated in terms of mechanical, chemical and cellular response. They display excellent mechanical performance, which is augmented by the CNFs, with Young’s moduli and conductivity reaching 534.7 ± 2.7 kPa and 4.1 × 10− 4 ± 2 × 10− 5 S/cm respectively. CNF incorporation enhances shear-thinning behaviour, allowing ease of 3-D printing. Invitro studies indicate improved cellular proliferation compared to controls. These conductive hydrogels have the potential to be used in a myriad of TE strategies, particularly for those focused on the incorporation of electroconductive components for applications such as cardiac or neuronal TE strategies.
Keywords: Electroactive | Hydrogels | Tissue engineering