Gelatin as Biomaterial for Tissue Engineering Echave, Mari C; Saenz del Burgo, Laura; Pedraz, Jose L ...
Current pharmaceutical design,
01/2017, Letnik:
23, Številka:
24
Journal Article
Recenzirano
Tissue engineering is considered one of the most important therapeutic strategies of regenerative medicine. The main objective of these new technologies is the development of substitutes made with ...biomaterials that are able to heal, repair or regenerate injured or diseased tissues and organs. These constructs seek to unlock the limited ability of human tissues and organs to regenerate. In this review, we highlight the convenient intrinsic properties of gelatin for the design and development of advanced systems for tissue engineering. Gelatin is a natural origin protein derived from collagen hydrolysis. We outline herein a state of the art of gelatin-based composites in order to overcome limitations of this polymeric material and modulate the properties of the formulations. Control release of bioactive molecules, formulations with conductive properties or systems with improved mechanical properties can be obtained using gelatin composites. Many studies have found that the use of calcium phosphate ceramics and diverse synthetic polymers in combination with gelatin improve the mechanical properties of the structures. On the other hand, polyaniline and carbon-based nanosubstrates are interesting molecules to provide gelatin-based systems with conductive properties, especially for cardiac and nerve tissue engineering. Finally, this review provides an overview of the different types of gelatin-based structures including nanoparticles, microparticles, 3D scaffolds, electrospun nanofibers and in situ gelling formulations. Thanks to the significant progress that has already been made, along with others that will be achieved in a near future, the safe and effective clinical implementation of gelatin-based products is expected to accelerate and expand shortly.
2D heterostructured materials combining ultrathin nanosheet morphology, defined pore configuration, and stable hybrid compositions, have attracted increasing attention for fast mass transport and ...charge transfer, which are highly desirable features for efficient energy storage. Here, the chemical space of 2D–2D heterostructures is extended by covalently assembling covalent organic frameworks (COFs) on MXene nanosheets. Unlike most COFs, which are generally produced as solid powders, ultrathin 2D COF‐LZU1 grows in situ on aminated Ti3C2Tx nanosheets with covalent bonding, producing a robust MXene@COF heterostructure with high crystallinity, hierarchical porosity, and conductive frameworks. When used as lithium hosts in Li metal batteries, lithium storage and charge transport are significantly improved. Both spectroelectrochemical and theoretical analyses demonstrate that lithiated COF channels are important as fast Li+ transport layers, by which Li ions can be precisely nucleated. This affords dendrite‐free and fast‐charging anodes, which would be difficult to achieve using individual components.
Nanoporous 2D MXene@COF heterostructures are synthesized through the covalent assembly of COF‐LZU1 with an interface‐initiated imine bonding. MXene@COF exhibits high crystallinity, stability, and hierarchical porosity. The ordered 2D channels and uniform nucleation sites boost the Li deposition kinetics, resulting in dendrite‐free and fast‐charging lithium metal batteries.
Large bone defects resulting from fractures and disease are a medical concern, being often unable to heal spontaneously by the body's repair mechanisms. Bone tissue engineering (BTE) is a promising ...approach for treating bone defects through providing a template to guide osseous regeneration. 3D scaffolds with microstructure mimicking host bone are necessary in common BTE strategies. Bioactive glasses (BGs) attract researchers' attention as BTE scaffolds as they are osteoconductive and osteoinductive in certain formulations. In vivo animal models allow understanding and evaluation of materials' performance in the complex physiological environment, being an inevitable step before clinical trials. The aim of this paper is to review for the first time published research investigating the in vivo osseous regenerative capacity of 3D BG scaffolds in bone defect animal models, to better understand and evaluate the progress and future outlook of the use of such scaffolds in BTE. The literature analysis reveals that the regenerative capacity of BG scaffolds depends on several factors; including BG composition, fabrication method, scaffold microstructure and pore characteristics, in addition to scaffold pretreatment and whether or not the scaffolds are loaded with growth factors. In addition, animal species selected, defect size and implantation time affect the scaffold in vivo behavior and outcomes. The review of the literature also makes clear the difficulty encountered to compare different types of bioactive glass scaffolds in their bone forming ability. Even considering such limitations of the current state-of-the-art, results generated from animal bone defect models provide an essential source of information to guide the design of BG scaffolds in future.
Bioactive glasses are at the centre of increasing research efforts in bone tissue engineering as the number of research groups around the world carrying out research on this type of biomaterials continues to increase. However, there are no previous reviews in literature which specifically cover investigations of the performance of bioactive glass scaffolds in bone defect animal models. This is the topic of the present review, in which we have analysed comprehensively all available literature in the field. The review thus fills a gap in the biomaterials literature providing a broad platform of information for researchers interested in bioactive glasses in general and specifically in the outcomes of in vivo models. Bioactive glass scaffolds of different compositions tested in relevant bone defect models are covered.
Macrophages are key players of the innate immune system that can roughly be divided into the pro-inflammatory M1 type and the anti-inflammatory, pro-healing M2 type. While a transient initial ...pro-inflammatory state is helpful, a prolonged inflammation deteriorates a proper healing and subsequent regeneration. One promising strategy to drive macrophage polarization by biomaterials is precise control over biomaterial geometry. For regenerative approaches, it is of particular interest to identify geometrical parameters that direct human macrophage polarization. For this purpose, we advanced melt electrowriting (MEW) towards the fabrication of fibrous scaffolds with box-shaped pores and precise inter-fiber spacing from 100 μm down to only 40 μm. These scaffolds facilitate primary human macrophage elongation accompanied by differentiation towards the M2 type, which was most pronounced for the smallest pore size of 40 μm. These new findings can be important in helping to design new biomaterials with an enhanced positive impact on tissue regeneration.
Additive manufacturing, with its ability to assemble a variety of materials in complex and customized architectures, is developing rapidly. The integration of technologies and materials into a ...sustainable production, however, is still challenging. The present investigation offers new functional glass-based products, from nearly room temperature processing, based on direct ink writing (DIW) of pastes from ‘light’ alkali activation (2.5 M NaOH) of pharmaceutical glass waste, added with 20 wt% of TiO2 nanoparticles. The inks were refined by the inclusion of porous glass microspheres (PGMs, 20–30 wt%), previously fabricated from fiber glass waste. Printed scaffolds, stabilized by simple drying (i.e. ‘unfired’), were successfully applied in the photodegradation of methylene blue. The degradation efficiency reached 100% within 75 min, and the 3D-printed composites could be easily separated from the solution for subsequent reuse. The degradation efficiency declined only by 7.5%, after 5 cycles.
The present study is dedicated to the manufacturing of highly porous triply periodic minimal surface (TPMS) constructs, fabricated from recycled end of life borosilicate pharmaceutical glass ...employing masked stereolithography. The structures were prepared from a simple blend of photocurable resin with glass powder (<38 µm). The gyroid model was selected with the porosity varying from 75 to 90%. Hot stage microscopy was applied to examine the glass sintering behaviour to improve the translucency of the 3D scaffolds. The obtained 3D scaffolds were dip-coated with TiO2 and further utilized for the photocatalytic degradation of dyes. The photocatalytic efficiency of the 3D scaffolds was evaluated by the degradation of methylene blue in water. It was found that 3D scaffolds coated with TiO2 showed a 40% higher degradation rate in comparison to bare 3D scaffolds under UV irradiation, which determines the significant role of TiO2 in the organic dye degradation. The better efficiency of 3D scaffolds coated with TiO2, compared with uncoated BSG 3D scaffolds is attributed to a better recombination rate, and the migration of electrons to the surface of the scaffold, where the charges participate in the photodecomposition of MB dye. The efficiency of the scaffolds was assessed for five consecutive cycles. The degradation efficiency after the fifth cycle was 75%, confirming the stability of the system.
Polymeric hydrogels are increasingly considered as scaffolds for tissue engineering due to their extraordinary resemblance with the extracellular matrix (ECM) of many tissues. As cell adhesion is a ...key factor in regulating important cell functions, hydrogel scaffolds are often functionalized or loaded with a variety of bioactive molecules that can promote adhesion. Interesting biomimetic approaches exploit the properties of mussel-inspired recombinant adhesive proteins. In this work, we prepared hydrogel scaffolds with a 50%w mixture of k-carrageenan (kC) and polyvinyl alcohol (PVA), by a two-step physical gelation process, and we coated them with Perna viridis foot protein-5β (Pvfp5β). The mechanical and morphological properties of hydrogels were investigated both after conditioning with typical cell culture media and also after coating with the Pvfp5β. The protein resulted strongly adsorbed onto the surface of the hydrogel and also able to penetrate in its interiors to a certain depth, mainly interacting with the kC component of the scaffold as resulted from the confocal analysis. Mouse embryonic fibroblasts NIH-3T3 were seeded on top of the hydrogels and cultured up to two weeks. The role of Pvfp5β in promoting cell adhesion, spreading and colonization of the scaffold was demonstrated.
Bone tissue repair strategies are gaining increasing relevance due to the growing incidence of bone disorders worldwide. Biochemical stimulation is the most commonly used strategy for cell ...regeneration, while the application of physical cues, including magnetic, mechanical, or electrical fields, is a promising, however, scarcely investigated field. This work reports on novel magnetoactive three-dimensional (3D) porous scaffolds suitable for effective proliferation of osteoblasts in a biomimetic microenvironment. This physically active microenvironment is developed through the bone-mimicking structure of the scaffold combined with the physical stimuli provided by a magnetic custom-made bioreactor on a magnetoresponsive scaffold. Scaffolds are obtained through the development of nanocomposites comprised of a piezoelectric polymer, poly(vinylidene fluoride) (PVDF), and magnetostrictive particles of CoFe2O4, using a solvent casting method guided by the overlapping of nylon template structures with three different fiber diameter sizes (60, 80, and 120 μm), thus generating 3D scaffolds with different pore sizes. The magnetoactive composites show a structure very similar to trabecular bone with pore sizes that range from 5 to 20 μm, owing to the inherent process of crystallization of PVDF with the nanoparticles (NPs), interconnected with bigger pores, formed after removing the nylon templates. It is found that the materials crystallize in the electroactive β-phase of PVDF and promote the proliferation of preosteoblasts through the application of magnetic stimuli. This phenomenon is attributed to both local magnetomechanical and magnetoelectric response of the scaffolds, which induce a proper cellular mechano- and electro-transduction process.
3D Scaffolds to Study Basic Cell Biology Hippler, Marc; Lemma, Enrico Domenico; Bertels, Sarah ...
Advanced materials,
06/2019, Letnik:
31, Številka:
26
Journal Article
Recenzirano
Odprti dostop
Mimicking the properties of the extracellular matrix is crucial for developing in vitro models of the physiological microenvironment of living cells. Among other techniques, 3D direct laser writing ...(DLW) has emerged as a promising technology for realizing tailored 3D scaffolds for cell biology studies. Here, results based on DLW addressing basic biological issues, e.g., cell‐force measurements and selective 3D cell spreading on functionalized structures are reviewed. Continuous future progress in DLW materials engineering and innovative approaches for scaffold fabrication will enable further applications of DLW in applied biomedical research and tissue engineering.
Among other techniques, direct laser writing (DLW) has emerged as a promising technology for realizing biofunctionalized 3D scaffolds mimicking the properties of the extracellular matrix. Results are reviewed based on DLW addressing basic biological questions, such as selective cell spreading or cell mechanics in a tailored 3D environment.
Silicones mixed with oxide fillers are interesting precursors for several bioactive glass-ceramics. A key point is represented by the coupling of synthesis and shaping, since highly porous bodies, in ...form of foams or scaffolds, are first manufactured with silicones in the polymeric state, at low temperature, and later subjected to ceramic transformation. After successful application of direct ink writing, the present study illustrates the tuning of silicone-based mixtures in order to form åkermanite (Ca2MgSi2O7) reticulated scaffolds by digital light processing. This implied the selection of commercial silicones, producing stable and homogeneous blends with a photocurable resin and enabling the manufacturing of defect-free printed scaffolds, before and after firing, without fillers. The blends were further refined with the introduction of fillers, followed by firing at 1100 °C, in air. Optimized samples (from H44 resin) and reactive fillers (including up to 4.5 wt.% borax additive), led to crack-free and phase-pure scaffolds with microporous struts.
PDF
