1,721,061 research outputs found
Morphology tuning of chitosan films via electrochemical deposition
No full textElectrochemical deposition is a versatile surface modification technology for the realization of advanced coatings for biomedical applications. Here, we studied the effects of bath composition on the morphology of chitosan films prepared via cathodic polarization of titanium substrates in acidic baths. Since electrocoagulation processes strongly depend on local reduction at the cathode, in turn affected by the acid/base equilibrium in solution, we examined three different water-based acid bath (1 g l− 1) at different pH ranges: acetic acid (pH 3–4), malonic acid (pH 2.7–3.2), and citric acid (pH = 2). Different coating morphologies, in terms of pore size and interconnection, were obtained when changing anion and solution pH. An increase in deposition mass per surface area was always observed when increasing polarization time, acetic acid bath showing the highest rates and yields and dried coating thickness up to 130 μm. High deposition rates resulted in porous coatings, due to the entrapment of H2 developed as a consequence of the local reduction processes. Gas evolution at the cathode surface determined the growth of pores in the deposit coatings and, depending on the process parameters, close vs. open porosity was observed.
The possibility of tuning surface morphology of this class of films pave the way for the design of a novel class of medical devices, in which surface assisted tissue engineering approaches can be exploited on conventional metals for the realization of a new class of implantable prostheses
Soft Scaffolds for Adipose Tissue Engineering Based on Poly Ethylene Glycol -Gelatin Systems
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Adipose-derived stem cells could sense the nano-scale cues as myogenic-differentiating factors
No full textMicroenvironmental cues, such as surface topography and substrate stiffness, may affect stem cells adhesion, morphology, alignment, proliferation and differentiation. Adipose derived stem cells (ASCs) have attracted considerable interest in regenerative medicine due to their easy isolation, extensive in vitro expandability and ability to differentiate along a number of different tissue-specific lineages. The aim of this work was to investigate ASCs adhesion, alignment and differentiation into myogenic lineage on nanofibrous polymeric scaffolds with anisotropic topography. Nanostructured scaffolds with randomized or parallel fibers were fabricated by electrospinning using polycaprolactone (PCL) and the polycarbonate-urethane ChronoFlex AL 80A (CFAL). Cells expressed myosin (fast skeletal) and tropomyosin in all surface topographies 7 days after seeding but myotube formation was only observed on CFAL scaffolds and only few myotubes were formed on PCL scaffolds. The different cell behavior could be ascribed to two main parameters: fibers dimensions and fibers orientation of the substrates that could result in a better myotube formation on CFAL scaffolds
Mucoadhesive chitosan-methylcellulose oral patches for the treatment of local mouth bacterial infections
Full text link: Mucoadhesive buccal patches are dosage forms promising for successful drug delivery. They show the distinctive advantages of long residence time on the oral mucosa and increased in situ drug bioavailability. In this context, electrophoretic deposition (EPD) of chitosan (CS) has been demonstrated as a simple and easily tunable technique to produce mucoadhesive buccal patches. However, CS-based buccal patches may suffer from weak mucoadhesion, which can impair their therapeutic effect. In this work, methylcellulose (MC), a widely investigated biopolymer in the biomedical area, was exploited to increase the mucoadhesive characteristic of pristine CS patches. CS-MC patches were obtained in a one-pot process via EPD, and the possibility of incorporating gentamicin sulfate (GS) as a model of a broad-spectrum antibiotic in the so-obtained patches was investigated. The resulting CS-MC patches showed high stability in a water environment and superior mucoadhesive characteristic (σadh = 0.85 ± 0.26 kPa, Wadh = 1192.28 ± 602.36 Pa mm) when compared with the CS control samples (σadh = 0.42 ± 0.22 kPa, Wadh = 343.13 ± 268.89 Pa mm), due to both the control of the patch porosity and the bioadhesive nature of MC. Furthermore, GS-loaded patches showed no in vitro cytotoxic effects by challenging L929 cells with material extracts and noteworthy antibacterial activity on both Gram-positive and Gram-negative bacterial strains
Decellularized fennel and dill leaves as possible 3D channel network in GelMA for the development of an in vitro adipose tissue model
Full text linkThe development of 3D scaffold-based models would represent a great step forward in cancer research, offering the possibility of predicting the potential in vivo response to targeted anticancer or anti-angiogenic therapies. As regards, 3D in vitro models require proper materials, which faithfully recapitulated extracellular matrix (ECM) properties, adequate cell lines, and an efficient vascular network. The aim of this work is to investigate the possible realization of an in vitro 3D scaffold-based model of adipose tissue, by incorporating decellularized 3D plant structures within the scaffold. In particular, in order to obtain an adipose matrix capable of mimicking the composition of the adipose tissue, methacrylated gelatin (GelMA), UV photo-crosslinkable, was selected. Decellularized fennel, wild fennel and, dill leaves have been incorporated into the GelMA hydrogel before crosslinking, to mimic a 3D channel network. All leaves showed a loss of pigmentation after the decellularization with channel dimensions ranging from 100 to 500 µm up to 3 μm, comparable with those of human microcirculation (5–10 µm). The photo-crosslinking process was not affected by the embedded plant structures in GelMA hydrogels. In fact, the weight variation test, performed on hydrogels with or without decellularized leaves showed a weight loss in the first 96 h, followed by a stability plateau up to 5 weeks. No cytotoxic effects were detected comparing the three prepared GelMA/D-leaf structures; moreover, the ability of the samples to stimulate differentiation of 3T3-L1 preadipocytes in mature adipocytes was investigated, and cells were able to grow and proliferate in the structure, colonizing the entire microenvironment and starting to differentiate. The developed GelMA hydrogels mimicked adipose tissue together with the incorporated plant structures seem to be an adequate solution to ensure an efficient vascular system for a 3D in vitro model. The obtained results showed the potentiality of the innovative proposed approach to mimic the tumoral microenvironment in 3D scaffold-based models
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