Structure, morphology and cell affinity of poly(l-lactide) films surface-functionalized with chitosan nanofibers via a solid–liquid phase separation technique

Functionalized 3D-Printed PLA Biomimetic Scaffold for Repairing Critical-Size Bone Defects

The treatment of critical-size bone defects remains a complicated clinical challenge. Recently, bone tissue engineering has emerged as a potential therapeutic approach for defect repair. This study examined the biocompatibility and repair efficacy of hydroxyapatite-mineralized bionic polylactic acid (PLA) scaffolds, which were prepared through a combination of 3D printing technology, plasma modification, collagen coating, and hydroxyapatite mineralization coating techniques. Physicochemical analysis, mechanical testing, and in vitro and animal experiments were conducted to elucidate the impact of structural design and microenvironment on osteogenesis. Results indicated that the PLA scaffold exhibited a porosity of 84.1% and a pore size of 350 μm, and its macrostructure was maintained following functionalization modification. The functionalized scaffold demonstrated favorable hydrophilicity and biocompatibility and promoted cell adhesion, proliferation, and the expression of osteogenic genes such as ALP, OPN, Col-1, OCN, and RUNX2. Moreover, the scaffold was able to effectively repair critical-size bone defects in the rabbit radius, suggesting a novel strategy for the treatment of critical-size bone defects.

Polysaccharide-based nanofibers for pharmaceutical and biomedical applications: A review

Nanofibers are fibrous nanocarriers that can be synthesized from natural polymers, synthetic polymers, semiconducting materials, composite materials, and carbon-based materials. Recently, natural polysaccharides-based nanofibers are gaining attention in the field of pharmaceuticals and biomedical as these are biocompatible, biodegradable, non-toxic, and economic. Nanofibers can deliver a significant amount of drug to the targeted site and provide effective interaction of therapeutic agent at the site of action due to a larger surface area. Other important advantages of nanofibers are low density, high porosity, small pore size, high mechanical strength, and low cost. In this review, natural polysaccharides such as alginate, pullulan, hyaluronic acid, dextran, cellulose, chondroitin sulfate, chitosan, xanthan gum, and gellan gum are discussed for their characteristics, pharmaceutical utility, and biomedical applications. The authors have given particular emphasis to the several fabrication processes that utilize these polysaccharides to form nanofibers, and their recent updates in pharmaceutical applications such as drug delivery, tissue engineering, skin disorders, wound-healing dressings, cancer therapy, bioactive molecules delivery, anti-infectives, and solubility enhancement. Despite these many advantages, nanofibers have been explored less for their scale-up and applications in advanced therapeutic delivery.

Correlation between Surface Properties of Polystyrene and Polylactide Materials and Fibroblast and Osteoblast Cell Line Behavior: A Critical Overview of the Literature

Bone reconstruction remains an important challenge today in several clinical situations, notably regarding the control of the competition occurring during proliferation of osteoblasts and fibroblasts. Polystyrene and polylactide are reference materials in the biomedical field. Therefore, it could be expected from the literature that clear correlations have been already established between the behavior of fibroblasts or osteoblasts and the surface characteristics of these materials. After an extensive analysis of the literature, although general trends could be established, our critical review has highlighted the need to develop a more in-depth analysis of the surface properties of these materials. Moreover, the large variation noticed in the experimental conditions used for in vitro animal cell studies impairs comparison between studies. From our comprehensive review on this topic, we have suggested several parameters that would be valuable to standardize to integrate the data from the literature and improve our knowledge on the cell-material interactions.

Fabrication Strategies of Scaffolds for Delivering Active Ingredients for Tissue Engineering

Designing scaffolds with optimum properties is an essential factor for tissue engineering success. They can be seeded with isolated cells or loaded with drugs to stimulate the body ability to repair or regenerate the injured tissues by acting as centers for new tissue formation. Recently, scaffolds gained a significant interest as principal candidates for tissue engineering due to overcoming the autograft or allograft's associated problems. The advancement of the tissue engineering field relies mainly on the introduction of new biomaterials for scaffolds' fabrication. This review presents and criticizes different scaffolds' fabrication techniques with particular emphasis on the fibrous, injectable in situ forming, foam, 3D freeze-dried, 3D printed, and 4D scaffolds. This article highlights on scaffolds' composition which would be beneficial for developing scaffolds that could potentially help to meet the demand for both drug delivery and tissue regeneration.

Probing polydopamine adhesion to protein and polymer films: microscopic and spectroscopic evaluation

Polydopamine has been found to be a biocompatible polymer capable of supporting cell growth and attachment, and to have antibacterial and antifouling properties. Together with its ease of manufacture and application, it ought to make an ideal biomaterial and function well as a coating for implants. In this paper, atomic force microscope was used to measure the adhesive forces between polymer-, protein- or polydopamine-coated surfaces and a silicon nitride or polydopamine-functionalised probes. Surfaces were further characterised by contact angle goniometry, and solutions by circular dichroism. Polydopamine was further characterised with infrared spectroscopy and Raman spectroscopy. It was found that polydopamine functionalisation of the atomic force microscope probe significantly reduced adhesion to all tested surfaces. For example, adhesion to mica fell from 0.27 ± 0.7 to 0.05 ± 0.01 nN nm-1. The results suggest that polydopamine coatings are suitable to be used for a variety of biomedical applications.

Biomaterials-based nanofiber scaffold: targeted and controlled carrier for cell and drug delivery

Nanofiber scaffold formulations (diameter less than 1000 nm) were successfully used to deliver the drug/cell/gene into the body organs through different routes for an effective treatment of various diseases. Various fabrication methods like drawing, template synthesis, fiber-mesh, phase separation, fiber-bonding, self-assembly, melt-blown, and electrospinning are successfully used for fabrication of nanofibers. These formulations are widely used in various fields such as tissue engineering, drug delivery, cosmetics, as filter media, protective clothing, wound dressing, homeostatic, sensor devices, etc. The present review gives a detailed account on the need of the nanofiber scaffold formulation development along with the biomaterials and techniques implemented for fabrication of the same against innumerable diseases. At present, there is a huge extent of research being performed worldwide on all aspects of biomolecules delivery. The unique characteristics of nanofibers such as higher loading efficiency, superior mechanical performance (stiffness and tensile strength), controlled release behavior, and excellent stability helps in the delivery of plasmid DNA, large protein drugs, genetic materials, and autologous stem-cell to the target site in the future.

Estudo das células Neuro2A sobre os biomateriais PCL e PLLA

Os biomateriais poli L-ácido lático (PLLA) e o poli caprolactona (PCL) são os polímeros mais estudadas na área dos materiais bioreabsorvíveis. Dentre as suas principais características que contribuem para a interação celular, temos a especificidade química da superfície, elétrica, hidrofobicidade e topografia. Ainda, observa-se o tempo de degradação, porosidade, biocompatibilidade com o tecido biológico, bem como, a confecção com as mais variadas formas e dimensões. Já a prática da cultura celular, tem como objetivo estudar a adesão, migração, diferenciação e a proliferação celular utilizando-se um determinado material ou substância. Contudo, poucos trabalhos utilizando os biomateriais ora supracitados e a aplicação em células neuro2A foram realizados. Sabe-se que este tipo celular é derivado de células embrionárias da crista neural, as quais originam em neurônios simpáticos e apresentam como característica a imortalidade, portanto, são excelentes modelos em ensaios in vitro. Nesse sentido, o presente estudo avalia a adesão e a proliferação desta linhagem celular sobre os biopolímeros poli caprolactona (PCL) e poli L-ácido lático (PLLA).