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1 december 2019, Contains fulltext : 215385.pdf (publisher's version ) (Closed access)

1 augustus 2019, Item does not contain fulltext, INTRODUCTION: Biomaterials have provided a wide range of exciting opportunities in tissue engineering and regenerative medicine. Gelatin, a collagen-derived natural biopolymer, has been extensively used in regenerative medicine applications over the years, due to its cell-responsive properties and the capacity to deliver a wide range of biomolecules. AREAS COVERED: The most relevant properties of gelatin as biomaterial are presented together with its main therapeutic applications. The latter includes drug delivery systems, tissue engineering approaches, potential uses as ink for 3D/4D Bioprinting, and its relevance in organ-on-a-chip platforms. EXPERT OPINION: Advances in polymer chemistry, mechanobiology, imaging technologies, and 3D biofabrication techniques have expanded the application of gelatin in multiple biomedical research applications ranging from bone and cartilage tissue engineering, to wound healing and anti-cancer therapy. Here, we highlight the latest advances in gelatin-based approaches within the fields of biomaterial-based drug delivery and tissue engineering together with some of the most relevant challenges and limitations.

Contains fulltext : 216097.pdf (publisher's version ) (Closed access)

1 september 2019, Item does not contain fulltext, Given their native-like biological properties, high growth factor retention capacity and porous nature, sulfated-polysaccharide-based scaffolds hold great promise for a number of tissue engineering applications. Specifically, as they mimic important properties of tissues such as bone and cartilage they are ideal for orthopaedic tissue engineering. Their biomimicry properties encompass important cell-binding motifs, native-like mechanical properties, designated sites for bone mineralisation and strong growth factor binding and signaling capacity. Even so, scientists in the field have just recently begun to utilise them as building blocks for tissue engineering scaffolds. Most of these efforts have so far been directed towards in vitro studies, and for these reasons the clinical gap is still substantial. With this review paper, we have tried to highlight some of the important chemical, physical and biological features of sulfated-polysaccharides in relation to their chondrogenic and osteogenic inducing capacity. Additionally, their usage in various in vivo model systems is discussed. The clinical studies reviewed herein paint a promising picture heralding a brave new world for orthopaedic tissue engineering.

Contains fulltext : 215393.pdf (publisher's version ) (Closed access)

Item does not contain fulltext, Bone tissue engineering is an emerging medical field that has been developed in recent years to address pathologies with limited ability of bones to regenerate. Here we report the fabrication and characterization of microbial transglutaminase crosslinked gelatin-based scaffolds designed for serving as both cell substrate and growth factor release system. In particular, morphological, biomechanical and biological features have been analyzed. The enzyme ratio applied during the fabrication of the scaffolds affects the swelling capacity and the mechanical properties of the final structure. The developed systems are not cytotoxic according to the biocompatibility tests. The biological performance of selected formulations was studied using L-929 fibroblasts, D1 MSC and MG63 osteoblasts. Moreover, scaffolds allowed efficient osteogenic differentiation and signaling of MSCs. MSC cultured on the scaffolds not only presented lower proliferative and stemness profile, but also increased expression of osteoblast-related genes (Col1a1, Runx2, Osx). Furthermore, the in vitro release kinetics of vascular endothelial growth factor (VEGF) and bone morphogenetic protein -2 (BMP-2) from the scaffolds were also investigated. The release of the growth factors produced from the scaffolds followed a first order kinetics. These results highlight that the scaffolds designed and developed in this work may be suitable candidates for bone tissue regeneration purposes.

Contains fulltext : 215313.pdf (publisher's version ) (Open Access), Given their durability and long-term stability, self-healable hydrogels have, in the past few years, emerged as promising replacements for the many brittle hydrogels currently being used in preclinical or clinical trials. To this end, the incompatibility between hydrogel toughness and rapid self-healing remains unaddressed, and therefore most of the self-healable hydrogels still face serious challenges within the dynamic and mechanically demanding environment of human organs/tissues. Furthermore, depending on the target tissue, the self-healing hydrogels must comply with a wide range of properties including electrical, biological, and mechanical. Notably, the incorporation of nanomaterials into double-network hydrogels is showing great promise as a feasible way to generate self-healable hydrogels with the above-mentioned attributes. Here, the recent progress in the development of multifunctional and self-healable hydrogels for various tissue engineering applications is discussed in detail. Their potential applications within the rapidly expanding areas of bioelectronic hydrogels, cyborganics, and soft robotics are further highlighted.

Item does not contain fulltext, Millions of people worldwide suffer from debilitating, progressive, and often permanent loss of vision without any viable treatment options. The complex physiological barriers of the eye contribute to the difficulty in developing novel therapies by limiting our ability to deliver therapeutics in a sustained and controlled manner; especially when attempting to deliver drugs to the posterior eye or trying to regenerate the diseased retina. Cell-based therapies offer a significant potential advancement in these situations. In particular, encapsulating, or immunoisolating, cells within implantable, semi-permeable membranes has emerged as a clinically viable means of delivering therapeutic molecules to the eye for indefinite periods of time. The optimization of encapsulation device designs is occurring together with refinements in biomaterials, genetic engineering, and stem-cell production, yielding, for the first time, the possibility of widespread therapeutic use of this technology. Here, we highlight the status of the most advanced and widely explored iteration of cell encapsulation with an eye toward translating the potential of this technological approach to the medical reality.

[Abstract] Microencapsulation of pancreatic islets for the treatment of Type I Diabetes Mellitus (T1DM) generates a high quantity of empty microcapsules, resulting in high therapeutic graft volumes that can enhance the host’s immune response. We report a 3D printed microfluidic magnetic sorting device for microcapsules purification with the objective to reduce the number of empty microcapsules prior transplantation. In this study, INS1E pseudoislets were microencapsulated within alginate (A) and alginate-poly-L-lysine-alginate (APA) microcapsules and purified through the microfluidic device. APA microcapsules demonstrated higher mechanical integrity and stability than A microcapsules, showing better pseudoislets viability and biological function. Importantly, we obtained a reduction of the graft volume of 77.5% for A microcapsules and 78.6% for APA microcapsules. After subcutaneous implantation of induced diabetic Wistar rats with magnetically purified APA microencapsulated pseudoislets, blood glucose levels were restored into normoglycemia (<200 mg/dL) for almost 17 weeks. In conclusion, our described microfluidic magnetic sorting device represents a great alternative approach for the graft volume reduction of microencapsulated pseudoislets and its application in T1DM disease.