Inorganic Nanomaterials in Tissue Engineering

In recent decades, the demand for replacement of damaged or broken tissues has increased; this poses the attention on problems related to low donor availability. For this reason, researchers focused their attention on the field of tissue engineering, which allows the development of scaffolds able to mimic the tissues’ extracellular matrix. However, tissue replacement and regeneration are complex since scaffolds need to guarantee an adequate hierarchical structured morphology as well as adequate mechanical, chemical, and physical properties to stand the stresses and enhance the new tissue formation. For this purpose, the use of inorganic materials as fillers for the scaffolds has gained great interest in tissue engineering applications, due to their wide range of physicochemical properties as well as their capability to induce biological responses. However, some issues still need to be faced to improve their efficacy. This review focuses on the description of the most effective inorganic nanomaterials (clays, nano-based nanomaterials, metal oxides, metallic nanoparticles) used in tissue engineering and their properties. Particular attention has been devoted to their combination with scaffolds in a wide range of applications. In particular, skin, orthopaedic, and neural tissue engineering have been considered.Horizon 2020 Research and Innovation Programme 81460

Electrospun nanofibers for improved angiogenesis: Promises for tissue engineering applications

Angiogenesis (or the development of new blood vessels) is a key event in tissue engineering and regenerative medicine; thus, a number of biomaterials have been developed and combined with stem cells and/or bioactive molecules to produce three-dimensional (3D) pro-angiogenic constructs. Among the various biomaterials, electrospun nanofibrous scaffolds offer great opportunities for pro-angiogenic approaches in tissue repair and regeneration. Nanofibers made of natural and synthetic polymers are often used to incorporate bioactive components (e.g., bioactive glasses (BGs)) and load biomolecules (e.g., vascular endothelial growth factor (VEGF)) that exert pro-angiogenic activity. Furthermore, seeding of specific types of stem cells (e.g., endothelial progenitor cells) onto nanofibrous scaffolds is considered as a valuable alternative for inducing angiogenesis. The effectiveness of these strategies has been extensively examined both in vitro and in vivo and the outcomes have shown promise in the reconstruction of hard and soft tissues (mainly bone and skin, respectively). However, the translational of electrospun scaffolds with pro-angiogenic molecules or cells is only at its beginning, requiring more research to prove their usefulness in the repair and regeneration of other highly-vascularized vital tissues and organs. This review will cover the latest progress in designing and developing pro-angiogenic electrospun nanofibers and evaluate their usefulness in a tissue engineering and regenerative medicine setting

Nanotechnology in peripheral nerve repair and reconstruction

The recent progress in biomaterials science and development of tubular conduits (TCs) still fails in solving the current challenges in the treatment of peripheral nerve injuries (PNIs), in particular when disease-related and long-gap defects need to be addressed. Nanotechnology-based therapies that seemed unreachable in the past are now being considered for the repair and reconstruction of PNIs, having the power to deliver bioactive molecules in a controlled manner, to tune cellular behavior, and ultimately guide tissue regeneration in an effective manner. It also offers opportunities in the imaging field, with a degree of precision never achieved before, which is useful for diagnosis, surgery and in the patientâ s follow-up. Nanotechnology approaches applied in PNI regeneration and theranostics, emphasizing the ones that are moving from the lab bench to the clinics, are herein overviewed.The authors acknowledge the Portuguese Foundation for Science and Technology (FCT) for the financial support provided to Joaquim M. Oliveira (IF/01285/2015) and Joana Silva-Correia (IF/00115/2015) under the program “Investigador FCT”.info:eu-repo/semantics/publishedVersio

Development of machines to engineer biocompatible matrices in ligament, filtering and 3D cell culture applications.

This thesis investigates three possible applications of engineered matrices manufactured from Polycaprolactone and Nylon-6 using electrospinning techniques. A method to manufacture bio compatible scaffolds for biomedical applications was studied. The scaffold was manufactured using a Polycaprolactone-PEGDA matrix to increase the viability of growth of cells. Mouse osteoblast cells were cultured on the samples and incubated to check for viability of the cells. The procedure to analyze the samples were not conclusive to show the viability of cells within the samples tested. The use of electrospun Polycaprolactone nanofiber cloth as a functional air filter was tested. As a model for analysis the filters were exposed to a steady stream of air that was polluted by tobacco smoke. The filters were weighed before and after exposure to find the effectivity of filtration. The filters were also imaged using X-ray diffraction to show the effectivity of filtration. The analysis shows that the weight of the filter after filtration was increased by up to 12% by weight. Procedures to manufacture artificial Anterior Cruciate Ligament were investigated. Mechanical properties of the artificial ACL were compared to the properties of ACL harvested from three rabbits. Samples for comparison were made from Polycaprolactone, Nylon-6 and Polycaprolactone-Nylon-6 twisted pair, Polycaprolactone Braided triplet. Prepared samples were broken in a tensile testing machine and the tensile properties were compared to values for the ACL harvested from the host rabbit. The research shows that the samples made were not able to reach the capabilities of the native rabbit ACL

Methacrylated Collagen and HNT Composite Hydrogels for Application in Bone Tissue Regeneration

Fractures and segmental bone defects are the primary cause of patient morbidity and brings a substantial economic burden to the healthcare system. Bone grafts used for bone injuries, tumors, and other pathologies related to poor fracture healing in the United States cost considerable money each year. The total cost of treating bone defects is about 5 billion US dollars. Autologous bone transplantation is the ideal method for the treatment of bone defects. However, their clinical results are variable and increase postoperative morbidity (especially at the donor site) and surgical costs. To circumvent these limitations, tissue engineering and cell-based therapies have been proposed as alternative methods to induce and promote bone repair. In this study, we have developed a composite photo-crosslinked hydrogel with favorable mechanical properties and tunable bioactive properties. Furthermore, this composite hydrogel system, when combined with 3D printed scaffolds, can be modified to meet various applications for bone tissue regeneration applications. In this study, we identified the optimal combination between different concentrations of halloysite nanotubes (HNTs), strontium coated HNTs (SrHNTs), bone morphogenetic protein 2 (BMP-2), collagen methacrylated (COMA), and cross-linking time to develop a suitable scaffold. The scaffold is biocompatible and biodegradable, but also antibacterial and should promote faster healing. The results suggest that gentamicin+SrHNTs+BMP-2 COMA hydrogel combined with a polycaprolactone (PCL) scaffold provides an optimal scaffold that can match the mechanical properties of bone. The next stage is to explore the scaffolds’ application in biomedical engineering. To do this, animal testing will need to be performed. If the scaffold works in the animal model it will provide a meaningful treatment plan for bone tissue repair and regeneration

LONG CHAIN POLYMERIC CARBOHYDRATE DEPENDENT NANOCOMPOSITES IN TISSUE ENGINEERING

The use of nanomedicine has increased enormously, especially in the field of gene delivery and targeted drug delivery. The objective of current review to identify long-chain polymeric carbohydrate dependent nano-composites in tissue engineering such gellan gum incorporated TiO2 nanotubes, Poly(vinyl) alcohol-gellan gum-based nanofiber, cross-linked gellan/pva nanofibers, nanocellulose reinforced gellan-gum hydrogels, dextran and sol-gel derived bioactive glass-ceramic nanoparticles, aminated β-cyclodextrin-modified-carboxylated magnetic cobalt/nanocellulose composite, chitosan-chitin nanocrystal composite scaffolds, sodium alginate-xanthan gum-based nano-composite scaffolds, nano-hydroxyapatite  pullulan/dextran polysaccharide composite, chitosan/carbon nanofibers scaffolds, nano-bio composite scaffold of chitosan–gelatin–alginate–hydroxyapatite, alginate/gelatin scaffolds with homogeneous nano apatite coating,nano-hydroxyapatite-alginate-gelatinmicrocapsule, poly(ε-caprolactone)/keratin nano fibrousmats, keratin nanoparticles-coating electrospun pva nanofiber, nano-hydroxyapatite/chitosan/chondroitin sulfate/hyaluronic acid and chitosan/chondroitin sulfate/nano-bioglass. The current review has identified a list of medicinal herbs that have been incorporated into long chain polymeric carbohydrate-based nano-composites.                    Peer Review History: Received 15 July 2020; Revised 13 August; Accepted 28 August, Available online 15 September 2020 Academic Editor: Essam Mohamed Eissa, Beni-Suef University, Egypt, [email protected] UJPR follows the most transparent and toughest ‘Advanced OPEN peer review’ system. The identity of the authors and, reviewers will be known to each other. This transparent process will help to eradicate any possible malicious/purposeful interference by any person (publishing staff, reviewer, editor, author, etc) during peer review. As a result of this unique system, all reviewers will get their due recognition and respect, once their names are published in the papers. We expect that, by publishing peer review reports with published papers, will be helpful to many authors for drafting their article according to the specifications. Auhors will remove any error of their article and they will improve their article(s) according to the previous reports displayed with published article(s). The main purpose of it is ‘to improve the quality of a candidate manuscript’. Our reviewers check the ‘strength and weakness of a manuscript honestly’. There will increase in the perfection, and transparency. Received file:                Reviewer's Comments: Average Peer review marks at initial stage: 6.5/10 Average Peer review marks at publication stage: 8.0/10 Reviewer(s) detail: Shahin Gavanji, World Academy of Medical Sciences, Iran,  [email protected] Dr. Asia Selman Abdullah, University of Basrah, Iraq, [email protected] Similar Articles: HEATING EFFECT ON PHYTOCHEMICAL AND PROXIMATE CONTENTS OF COOKED AQUEOUS EXTRACT OF PHASEOLUS VULGARIS (KIDNEY BEANS

Nanotechnology Approaches in Chronic Wound Healing

Significance: The incidence of chronic wounds is increasing due to our aging population and the augment of people afflicted with diabetes. With the extended knowledge on the biological mechanisms underlying these diseases, there is a novel influx of medical technologies into the conventional wound care market. Recent Advances: Several nanotechnologies have been developed demonstrating unique characteristics that address specific problems related to wound repair mechanisms. In this review, we focus on the most recently developed nanotechnology-based therapeutic agents and evaluate the efficacy of each treatment in in vivo diabetic models of chronic wound healing. Critical Issues: Despite the development of potential biomaterials and nanotechnology-based applications for wound healing, this scientific knowledge is not translated into an increase of commercially available wound healing products containing nanomaterials. Future Directions: Further studies are critical to provide insights into how scientific evidences from nanotechnology-based therapies can be applied in the clinical setting

Chitosan nanocomposites based on distinct inorganic fillers for biomedical applications

AbstractChitosan (CHI), a biocompatible and biodegradable polysaccharide with the ability to provide a non-protein matrix for tissue growth, is considered to be an ideal material in the biomedical field. However, the lack of good mechanical properties limits its applications. In order to overcome this drawback, CHI has been combined with different polymers and fillers, leading to a variety of chitosan-based nanocomposites. The extensive research on CHI nanocomposites as well as their main biomedical applications are reviewed in this paper. An overview of the different fillers and assembly techniques available to produce CHI nanocomposites is presented. Finally, the properties of such nanocomposites are discussed with particular focus on bone regeneration, drug delivery, wound healing and biosensing applications

In vitro evaluation of human endometrial stem cell-derived osteoblast-like cells’ behavior on gelatin/collagen/bioglass nanofibers’ scaffolds

New biomimetic nanocomposite scaffold was prepared by the combination of nanofibrilar bioglass containing copper ion as the inorganic phase and gelatin/collagen as the organic phase of bone tissue. In this study for fabrication of the scaffold, freeze drying and electrospinning methods were used, and genipin was used as the cross-linking agent for increasing the mechanical properties of the scaffold. The growth and viability of human endometrial stem cell-derived osteoblast-like cells were investigated on this biomimetic scaffold. Cellular biocompatibility assays illustrated that this scaffold has more viabilities and osteoblast growths in comparison with two-dimensional culture. Copper ion increased growth of the osteoblasts on nanocomposite scaffold containing nanofibrous bioglass. Thus, the results obtained from this study indicate that the prepared scaffold is suitable for osteoblast growth and attachment; thus, potentially, this nanocomposite scaffold is an appropriate scaffold for bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2210–2219, 2016