Application of chitosan with different molecular weights in cartilage tissue engineering.

Cartilage tissue engineering involves the invention of novel implantable cartilage replacement materials to help heal cartilage injuries that do not heal themselves, aiming to overcome the shortcomings of current clinical cartilage treatments. Chitosan has been widely used in cartilage tissue engineering because of its similar structure to glycine aminoglycan, which is widely distributed in connective tissues. The molecular weight, as an important structural parameter of chitosan, affects not only the method of chitosan composite scaffold preparation but also the effect on cartilage tissue healing.

The Treatment of Keloid Scars via Modulating Heterogeneous Gelatin-Structured Composite Microneedles to Control Transdermal Dual-Drug Release.

Keloid scarring is an abnormal scar disease characterised by excessive proliferation of fibroblasts and over-deposition of collagen during wound healing. Although various treatments for keloid scars have been developed, preventive medicine is believed to be a promising strategy. The skin barrier limits the gentle topical administration of medicaments such as creams and hydrogel dressings, resulting in reduced therapeutic efficacy.

High-Density Horizontal Stacking of Chondrocytes via the Synergy of Biocompatible Magnetic Gelatin Nanocarriers and Internal Magnetic Navigation for Enhancing Cartilage Repair.

Osteoarthritis (OA) is a globally occurring articular cartilage degeneration disease that adversely affects both the physical and mental well-being of the patient, including limited mobility. One major pathological characteristic of OA is primarily related to articular cartilage defects resulting from abrasion and catabolic and proinflammatory mediators in OA joints. Although cell therapy has hitherto been regarded as a promising treatment for OA, the therapeutic effects did not meet expectations due to the outflow of implanted cells.

A smart injectable composite hydrogel with magnetic navigation and controlled glutathione release for promoting chondrocyte array and self-healing in damaged cartilage tissue.

Injectable cell-based hydrogels allow surgical operation in a minimally invasive way for articular cartilage lesions but the chondrocytes in the injectable hydrogels are difficultly arrayed and fixed at the site of interest to repair the cartilage tissue. In this study, an injectable hyaluronic acid-polyacrylic acid (HA-pAA) hydrogel was first synthesized using hyaluronic acid-cyclodextrin (HA-CD) and polyacrylic acid-ferrocene (pAA-Fc) to provide cell-delivery and self-healing. To promote the cell fixation and alignment, porous poly(lactic--glycolic acid) (PLGA) magnetic microcapsules (PPMMs) with glutathione (GSH) loaded and iron oxide nanoparticles (IO) located in the shell were designed.

Protein-based soft actuator with high photo-response and easy modulation for anisotropic cell alignment and proliferation in a liquid environment.

Cell alignment and elongation, which are critical factors correlated with differentiation and maturation in cell biology and tissue engineering, have been widely studied in organisms. Several strategies such as external mechanical strain, geometric topography, micropatterning approaches, and microfabricated substrates have been developed to guide cell alignment, but these methodologies cannot be used for easily denatured natural proteins to modulate the cell behaviour. Herein, for the first time, a novel biocompatible light-controlled protein-based bilayer soft actuator composed of elastin-like polypeptides (ELPs), silk fibroin (SF), graphene oxide (GO), and reduced graphene oxide (rGO), named ESGRG, is developed for efficiently driving cellular orientation and elongation with anisotropic features on soft actuator via remote NIR laser exposure.

4D spatiotemporal modulation of biomolecules distribution in anisotropic corrugated microwrinkles via electrically manipulated microcapsules within hierarchical hydrogel for spinal cord regeneration.

Although traditional 3D scaffolds or biomimetic hydrogels have been used for tissue engineering and regenerative medicine, soft tissue microenvironment usually has a highly anisotropic structure and a dynamically controllable deformation with various biomolecule distribution. In this study, we developed a hierarchical hybrid gelatin methacrylate-microcapsule hydrogel (HGMH) with Neurotrophin-3(NT-3)-loaded PLGA microcapsules to fabricate anisotropic structure with patterned NT-3 distribution (demonstrated as striped and triangular patterns) by dielectrophoresis (DEP). The HGMH provides a dynamic biomimetic sinuate-microwrinkles change with NT-3 spatial gradient and 2-stage time-dependent distribution, which was further simulated using a 3D finite element model.

Non-Invasive Blood Glucose Monitoring Technology: A Review.

In recent years, with the rise of global diabetes, a growing number of subjects are suffering from pain and infections caused by the invasive nature of mainstream commercial glucose meters. Non-invasive blood glucose monitoring technology has become an international research topic and a new method which could bring relief to a vast number of patients. This paper reviews the research progress and major challenges of non-invasive blood glucose detection technology in recent years, and divides it into three categories: optics, microwave and electrochemistry, based on the detection principle.

A Facile Fabrication of Biodegradable and Biocompatible Cross-Linked Gelatin as Screen Printing Substrates.

This study focuses on preparation and valuation of the biodegradable, native, and modified gelatin film as screen-printing substrates. Modified gelatin film was prepared by crosslinking with various crosslinking agents and the electrode array was designed by screen-printing. It was observed that the swelling ratio of C-2, crosslinked with glutaraldehyde and EDC/NHS (1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide) was found to be lower (3.

Using the interplay of magnetic guidance and controlled TGF-β release from protein-based nanocapsules to stimulate chondrogenesis.

Introduction: Stimulating the proliferation and differentiation of chondrocytes for the regeneration of articular cartilage is a promising strategy, but it is currently ineffective. Although both physical stimulation and growth factors play important roles in cartilage repair, their interplay remains unclear and requires further investigation. In this study, we aimed to clarify their contribution using a magnetic drug carrier that not only can deliver growth factors but also provide an external stimulation to cells in the two-dimensional environment.

Development of chondrocyte-seeded electrosprayed nanoparticles for repair of articular cartilage defects in rabbits.

Due to limited self-healing capacity in cartilages, there is a rising demand for an innovative therapy that promotes chondrocyte proliferation while maintaining its biofunctionality for transplantation. Chondrocyte transplantation has received notable attention; however, the tendencies of cell de-differentiation and de-activation of biofunctionality have been major hurdles in its development, delaying this therapy from reaching the clinic. We believe it is due to the non-stimulative environment in the injured cartilage, which is unable to provide sustainable physical and biological supports to the newly grafted chondrocytes.

Direct Reprogramming of Human Suspension Cells into Mesodermal Cell Lineages via Combined Magnetic Targeting and Photothermal Stimulation by Magnetic Graphene Oxide Complexes.

Suspension cells can provide a source of cells for cellular reprogramming, but they are difficult to transfect by nonviral vectors. An efficient and safe nonviral vector (GO-Fe O -PEI complexes) based on iron oxide nanoparticle (Fe O )-decorated graphene oxide (GO) complexed with polyethylenimine (PEI) for the first time is developed for delivering three individual episomal plasmids (pCXLE-hOCT3/4-shp53, pCXLE-hSK, and pCXLE-hUL) encoding pluripotent-related factors of Oct3/4, shRNA against p53, Sox2, Klf4, L-Myc, and Lin28 into human peripheral blood mononuclear cells (PBMCs) simultaneously. The combined treatment of magnetic stirring and near-infrared (NIR)-laser irradiation, which can promote contact between the complexes and floating cells and increase the cell membrane permeability, respectively, is used to conduct multiple physical stimulations for suspension PBMCs transfection.

Alternative approach of cell encapsulation by Volvox spheres.

Volvox sphere is a bio-mimicking concept of a biomaterial structure design able to encapsulate chemicals, drugs and/or cells. The aim of this study was to prepare Volvox spheres encapsulating AML12 liver cells and mesenchymal stem cells (MSCs) via a high voltage electrostatic field system. The results demonstrated that AML12 liver cells and MSCs could be successfully encapsulated into the inner spheres and the outer sphere of the Volvox spheres.

Enhanced anti-cancer activity by curcumin-loaded hydrogel nanoparticle derived aggregates on A549 lung adenocarcinoma cells.

To investigate the anti-cancer activity of curcumin-loaded hydrogel nanoparticle derived aggregates on A549 lung adenocarcinoma cells. Curcumin was incorporated with biopolymeric chitosan, gelatin, and hyaluronan nanoparticles using an electrostatic field system. Characteristics of curcumin-loaded aggregates were examined including size and morphology, incorporation efficiency, stability and in vitro release.

Evaluation of the ability of xanthan gum/gellan gum/hyaluronan hydrogel membranes to prevent the adhesion of postrepaired tendons.

After tendon-repair surgery, adhesion between the surgical tendon and the synovial sheath is often presented resulting in poor functional repair of the tendon. This may be prevented using a commercially available mechanical barrier implant, Seprafilm, which is composed of hyaluronan (HA) and carboxymethyl cellulose hydrogels. In a rat model, prepared membranes of various compositions of gellan gum (GG), xanthan gum (XG) and HA as well as Seprafilm were wrapped around repaired tendons and the adhesion of the tendons was examined grossly and histologically after 3 weeks of healing.

The biological effects of sex hormones on rabbit articular chondrocytes from different genders.

The aim of this study was to investigate the biological effects of sex hormones (17β-estradiol and testosterone) on rabbit articular chondrocytes from different genders. We cultured primary rabbit articular chondrocytes from both genders with varying concentration of sex hormones. We evaluate cell proliferation and biochemical functions by MTT and GAG assay.

Does low-intensity pulsed ultrasound treatment repair articular cartilage injury? A rabbit model study.

Background: Low-intensity pulsed ultrasound (LIPUS) regiment has been used to treat fractures with non-union and to promote bone union in general. The effect of LIPUS on articular cartilage metabolism has been characterized. Yet, the effect of LIPUS to repair articular cartilage injury remains unclear in vivo.

Preparation and evaluation of collagen I/ gellan gum/β-TCP microspheres as bone graft substitute materials.

Collagen I is the main component of protein in bone and exhibits many excellent applications in biomedical fields. Gellan gum possesses good biocompatible, biodegradable and good mechanical property, and shows great potentials as tissue engineering scaffold or cell culture substrate. Therefore, the aim of this study was to use collagen I, gellan gum and β-TCP to prepare collagen I/gellan gum/β-TCP microspheres by emulsion method as bone graft substitute materials.

Concept for E.coli detection using interdigitated microelectrode impedance sensor.

This paper presents the concept to detect Escherichia coli O157:H7 based on electrochemical impedance spectroscopy at interdigitated microelectrode. Interdigitated microelectrode structures was designed and fabricated, with glass as substrate material and gold electrodes. The performance of the sensors was studied by measuring the capacitance in air and impedance spectra in DI water.

Enhanced differentiation of rat MSCs into cardiomyocytes with 5-azacytidine/collagen I nano-molecules.

This study was to investigate the enhancement ability of 5-azacytidine (5-aza) and collagen I nano-molecules treatment to the differentiation of rat mesenchymal stem cells (MSCs) towards a cardiomyocytes in vitro. The results demonstrated that the size of the cells increased significantly and connecting with adjoining cells by forming myotube-like structures. Also, additional treatment of the MSCs with collagen I nano-fibrils significantly increased two transcription factors GATA-4 and Nkx2.

The production of volvox spheres and their potential application in multi-drugs encapsulation and release.

Volvox sphere is a bio-mimicking concept of an innovative biomaterial structure of a sphere that contains smaller microspheres which then encapsulate chemicals, drugs and/or cells. The volvox spheres were produced via a high-voltage electrostatic field system, using alginate as the primary material. Encapsulated materials tested in this study include staining dyes, nuclear fast red and trypan blue, and model drugs, bovine serum albumin (BSA) and cytochrome c (CytC).

Biomechanical comparison of axial load between cannulated locking screws and noncannulated cortical locking screws.

The goal of this study was to compare the biomechanical stability of cannulated locking screws and noncannulated cortical locking screws in a periarticular locking plate. Twelve fresh-frozen porcine tibias with a 1-cm gap created distal to the tibial plateau were used to simulate an unstable proximal tibial fracture. All specimens were fixed with a periarticular proximal lateral tibial locking plate and divided into 2 groups based on whether the proximal metaphyseal screw holes of the plate were inserted with either cannulated locking screws or noncannulated cortical locking screws.

Enhanced apoptotic effects of dihydroartemisinin-aggregated gelatin and hyaluronan nanoparticles on human lung cancer cells.

Recent studies suggest that dihydroartemisinin (DHA), a derivative of artemisinin isolated from the traditional Chinese herb Artemisia annua L., has anticancer properties. Due to poor water solubility, poor oral activity, and a short plasma half-life, large doses of DHA have to be injected to achieve the necessary bioavailability.

Intraosseous leiomyoma of the distal femur: a case report and review of literatures.

Background: Leiomyoma is a benign tumor of smooth-muscle origin. They most commonly derived from the uterus. Besides, they were also usually diagnosed in the gastrointestinal tract, skin, and mucous membranes.