Search results for "self-healing"
showing 10 items of 222 documents
Heat- and pH-induced BSA conformational changes, hydrogel formation and application as 3D cell scaffold
2016
Aggregation and gelation of globular proteins can be an advantage to generate new forms of nanoscale biomaterials based on the fibrillar architecture. Here, we report results obtained by exploiting the proteins' natural tendency to self-organize in 3D network, for the production of new material based on BSA for medical application. In particular, at five different pH values the conformational and structural changes of the BSA during all the steps of the thermal aggregation and gelation have been analyzed by FTIR spectroscopy. The macroscopic mechanical properties of these hydrogels have been obtained by rheological measurements. The microscopic structure of the gels have been studied by AFM…
Guanosine-5'-Monophosphate Polyamine Hybrid Hydrogels: Enhanced Gel Strength Probed by z-Spectroscopy.
2017
The self-assembling tendencies of guanosine-5'-monophosphate (GMP) can be drastically increased using polyamines, with potential applications in the production of biocompatible smart materials, as well as for the design of anti-tumoral drugs based on G-quadruplex stabilization. Results from scanning electron microscopy (SEM), wide angle X-ray scattering (WAXS), rheology and nuclear magnetic resonance (NMR) z-spectroscopy studies are presented.
Automated detection of protein unfolding events in atomic force microscopy force curves
2016
Atomic force microscopy is not only a high-resolution imaging device but also a mechanical machine, which can be used either to indent or stretch (soft) biomaterials. Due to the statistical nature of such materials (i.e., hydrogels or polymers) hundreds of force-distance curves are required to describe their mechanical properties. In this manuscript, we present an automated system for polymer unfolding detection based on continuous wavelet analysis. We have tested the automated program on elastin, which is an important protein that provides elasticity to tissues and organs. Our results show that elastin changes its mechanical behavior in the presence of electrolytes. In particular, we show …
Improved Models of Human Endometrial Organoids Based on Hydrogels from Decellularized Endometrium
2021
Organoids are three-dimensional (3D) multicellular tissue models that mimic their corresponding in vivo tissue. Successful efforts have derived organoids from primary tissues such as intestine, liver, and pancreas. For human uterine endometrium, the recent generation of 3D structures from primary endometrial cells is inspiring new studies of this important tissue using precise preclinical models. To improve on these 3D models, we decellularized pig endometrium containing tissue-specific extracellular matrix and generated a hydrogel (EndoECM). Next, we derived three lines of human endometrial organoids and cultured them in optimal and suboptimal culture expansion media with or without EndoEC…
Cutting-edge progress and challenges in stimuli responsive hydrogel microenvironment for success in tissue engineering today.
2020
The field of tissue engineering has numerous potential for modified therapeutic results and has been inspired by enhancements in bioengineering at the recent decades. The techniques of regenerating tissues and assembling functional paradigms that are responsible for repairing, maintaining, and revitalizing lost organs and tissues have affected the entire spectrum of health care studies. Strategies to combine bioactive molecules, biocompatible materials and cells are important for progressing the renewal of damaged tissues. Hydrogels have been utilized as one of the most popular cell substrate/carrier in tissue engineering since previous decades, respect to their potential to retain a 3D str…
Alginate/silica composite hydrogel as a potential morphogenetically active scaffold for three-dimensional tissue engineering
2013
Pursuing our aim to develop a biomimetic synthetic scaffold suitable for tissue engineering, we embedded bone cells, osteoblast-related SaOS-2 cells and osteoclast-like RAW 264.7 cells, into beads, formed of a Na-alginate-based or a silica-containing Na-alginate-based hydrogel matrix. The beads were incubated either separately (only one cell line in a culture dish) or co-incubated (SaOS-2-containing beads and RAW 264.7 beads). The alginate and alginate/silica hydrogel matrices were found not to impair the viability of the encapsulated cells. In these matrices the SaOS-2 cells retain their capacity to synthesize hydroxyapatite crystallites. The mechanical properties, including surface roughn…
Reversible Hydrogels with Switchable Diffusive Permeability
2021
Hydrogels are polymer networks swollen in water that are characterized by soft mechanics and high permeability. This makes them good candidates for separation and membrane technologies. The diffusion is controlled by the mesh size of the network, and this can be made tunable through the introduction of thermoresponsive polymers. However, this is still a developing field. To contribute to this development, a dual dynamic network is formed composed of four-arm polyethylene glycol precursors in which each arm is functionalized with both a terpyridine moiety capable of forming reversible metal–ligand complexes along with branches of poly(N-isopropylacrylamide) (pNIPAAm), which can be swit…
Acid‐Cleavable Poly(ethylene glycol) Hydrogels Displaying Protein Release at pH 5
2020
Abstract PEG is the gold standard polymer for pharmaceutical applications, however it lacks degradability. Degradation under physiologically relevant pH as present in endolysosomes, cancerous and inflammatory tissues is crucial for many areas. The authors present anionic ring‐opening copolymerization of ethylene oxide with 3,4‐epoxy‐1‐butene (EPB) and subsequent modification to introduce acid‐degradable vinyl ether groups as well as methacrylate (MA) units, enabling radical cross‐linking. Copolymers with different molar ratios of EPB, molecular weights (M n) up to 10 000 g mol−1 and narrow dispersities (Đ<1.05) were prepared. Both the P(EG‐co‐isoEPB)MA copolymer and the hydrogels showed pH‐…
Positive effects of an extracellular matrix hydrogel on rat anterior cruciate ligament fibroblast proliferation and collagen mRNA expression
2015
Summary Background/Objective We have previously shown that an extracellular matrix (ECM) bioscaffold derived from porcine small intestine submucosa (SIS) enhanced the healing of a gap injury of the medial collateral ligament as well as the central third defect of the patellar tendon. With the addition of a hydrogel form of SIS, we found that a transected goat anterior cruciate ligament (ACL) could also be healed. The result begs the research question of whether SIS hydrogel has positive effects on ACL fibroblasts (ACLFs) and thus facilitates ACL healing. Methods In the study, ECM-SIS hydrogel was fabricated from the digestion of decellularised and sterilised sheets of SIS derived from αGal-…
Lubricin is expressed in chondrocytes derived from osteoarthritic cartilage encapsulated in poly (ethylene glycol) diacrylate scaffold
2011
Osteoarthritis (OA) is characterized by degenerative changes within joints that involved quantitative and/or qualitative alterations of cartilage and synovial fluid lubricin, a mucinous glycoprotein secreted by synovial fibroblasts and chondrocytes. Modern therapeutic methods, including tissue-engineering techniques, have been used to treat mechanical damage of the articular cartilage but to date there is no specific and effective treatment. This study aimed at investigating lubricin immunohistochemical expression in cartilage explant from normal and OA patients and in cartilage constructions formed by Poly (ethylene glycol) (PEG) based hydrogels (PEG-DA) encapsulated OA chondrocytes. The e…