Tissue Engineering of Esophagus

The incidences of esophageal diseases like atresia, tracheoesophageal fistula, esophagitis, and even carcinoma rise rapidly worldwide. Traditional therapies such as surgery, chemotherapy, or/and radiotherapy, etc. always meet problems, leading to deterioration of the patients’ life quality and sometimes the reduced survival rate. Tissue‐engineered esophagus, a novel biologic substitute with tissue architecture and bio‐functions, has been believed to be a promising replacement in the future. However, the research of esophageal tissue engineering is still at the early stage. Considerable research has been focused on the issues of developing ideal scaffolds with optimal materials and fabrication methods. The in vivo tests and clinic attempts are being progressed

Nanomaterials-Based Wound Dressing for Advanced Management of Infected Wound

The effective prevention and treatment of bacterial infections is imperative to wound repair and the improvement of patient outcomes. In recent years, nanomaterials have been extensively applied in infection control and wound healing due to their special physiochemical and biological properties. Incorporating antibacterial nanomaterials into wound dressing has been associated with improved biosafety and enhanced treatment outcomes compared to naked nanomaterials. In this review, we discuss progress in the application of nanomaterial-based wound dressings for advanced management of infected wounds. Focus is given to antibacterial therapy as well as the all-in-one detection and treatment of bacterial infections. Notably, we highlight progress in the use of nanoparticles with intrinsic antibacterial performances, such as metals and metal oxide nanoparticles that are capable of killing bacteria and reducing the drug-resistance of bacteria through multiple antimicrobial mechanisms. In addition, we discuss nanomaterials that have been proven to be ideal drug carriers for the delivery and release of antimicrobials either in passive or in stimuli-responsive manners. Focus is given to nanomaterials with the ability to kill bacteria based on the photo-triggered heat (photothermal therapy) or ROS (photodynamic therapy), due to their unparalleled advantages in infection control. Moreover, we highlight examples of intelligent nanomaterial-based wound dressings that can detect bacterial infections in-situ while providing timely antibacterial therapy for enhanced management of infected wounds. Finally, we highlight challenges associated with the current nanomaterial-based wound dressings and provide further perspectives for future improvement of wound healing

Nanomaterials-Based Wound Dressing for Advanced Management of Infected Wound

The effective prevention and treatment of bacterial infections is imperative to wound repair and the improvement of patient outcomes. In recent years, nanomaterials have been extensively applied in infection control and wound healing due to their special physiochemical and biological properties. Incorporating antibacterial nanomaterials into wound dressing has been associated with improved biosafety and enhanced treatment outcomes compared to naked nanomaterials. In this review, we discuss progress in the application of nanomaterial-based wound dressings for advanced management of infected wounds. Focus is given to antibacterial therapy as well as the all-in-one detection and treatment of bacterial infections. Notably, we highlight progress in the use of nanoparticles with intrinsic antibacterial performances, such as metals and metal oxide nanoparticles that are capable of killing bacteria and reducing the drug-resistance of bacteria through multiple antimicrobial mechanisms. In addition, we discuss nanomaterials that have been proven to be ideal drug carriers for the delivery and release of antimicrobials either in passive or in stimuli-responsive manners. Focus is given to nanomaterials with the ability to kill bacteria based on the photo-triggered heat (photothermal therapy) or ROS (photodynamic therapy), due to their unparalleled advantages in infection control. Moreover, we highlight examples of intelligent nanomaterial-based wound dressings that can detect bacterial infections in-situ while providing timely antibacterial therapy for enhanced management of infected wounds. Finally, we highlight challenges associated with the current nanomaterial-based wound dressings and provide further perspectives for future improvement of wound healing

Natural polysaccharides promote chondrocyte adhesion and proliferation on magnetic nanoparticle/PVA composite hydrogels

This paper aims to investigate the synergistic effects of natural polysaccharides and inorganic nanoparticles on cell adhesion and growth on intrinsically cell non-adhesive polyvinyl alcohol (PVA) hydrogels. Previously, we have demonstrated that Fe2O3 and hydroxyapatite (nHAP) nanoparticles are effective in increasing osteoblast growth on PVA hydrogels. Herein, we blended hyaluronic acid (HA) and chondroitin sulfate (CS), two important components of cartilage extracellular matrix (ECM), with Fe2O3/nHAP/PVA hydrogels. The presence of these natural polyelectrolytes dramatically increased the pore size and the equilibrium swelling ratio (ESR) while maintaining excellent compressive strength of hydrogels. Chondrocytes were seeded and cultured on composite PVA hydrogels containing Fe2O3, nHAP and Fe2O3/nHAP hybrids and Fe2O3/nHAP with HA or CS. Confocal laser scanning microscopy (CLSM) and cell counting kit-8 (CCK-8) assay consistently confirmed that the addition of HA or CS promotes chondrocyte adhesion and growth on PVA and composite hydrogels. Particularly, the combination of HA and CS exhibited further promotion to cell adhesion and proliferation compared with any single polysaccharide. The results demonstrated that the magnetic composite nanoparticles and polysaccharides provided synergistic promotion to cell adhesion and growth. Such polysaccharide-augmented composite hydrogels may have potentials in biomedical applications. (c) 2015 Elsevier B.V. All rights reserved

Macroporous biphasic calcium phosphate scaffolds reinforced by poly-L-lactic acid/hydroxyapatite nanocomposite coatings for bone regeneration

Three-dimensional (3D) interconnected porous scaffolds with biomimetic hierarchical architectures and mechanical characteristics are critical for the success of bone regeneration. In this paper, biphasic calcium phosphate (BCP) scaffolds were coated with medical-grade poly-L-lactic acid/hydroxyapatite (mPLLA/HA) nanocomposites to create controlled surface roughness while remaining the interconnected porous structures. Such mPLLA/HA coatings substantially improved the compressive strength of the scaffolds to 3.17-3.95 MPa, in contrast to 0.31 MPa for the as-prepared bare porous BCP scaffolds. Moreover, these mPLLA/HA-coated porous scaffolds were demonstrated to provide excellent support to the growth and proliferation of human barrow mysenchymal stem cells (hBMSCs). The hBMSCs-seeded mPLLA/HA-coated scaffolds were implanted to large necrotic lesions in the rabbit femoral head. New bone tissues were observed after two months, followed by gradient new bone formation over months according to H&E and Masson staining analysis. These results suggest that the mPLLA/HA-coated BCP scaffolds with improved mechanical strength and osteogenesis may be applied for bone regeneration. (C) 2015 Elsevier B.V. All rights reserved

Hydroxyethyl Chitosan-Reinforced Polyvinyl Alcohol/Biphasic Calcium Phosphate Hydrogels for Bone Regeneration

info:eu-repo/semantics/publishe

Smart wound dressing for advanced wound management: Real-time monitoring and on-demand treatment

Timely and accurate assessment of wounds during the wound healing process is key for correct diagnosis and treatment decisions for wound repair. However, traditional wound management strategies often fail to provide timely and accurate information on wound status, thereby delaying or misleading treatments. Smart wound dressings that enable the in situ real-time monitoring of wound-related biomarkers, early diagnosis and on-demand treatment of adverse wound healing events, such as bacterial infection and inflammation, by integrating wearable sensors, advanced drug delivery systems and wireless communication technology have recently been developed and could improve wound management. In this review, we provided an overview of biomarkers, including temperature, pH, uric acid, glucose, reactive oxygen (ROS), oxygen and enzymes, related to adverse wound healing events and exiting sensors for detecting these biomarkers based on colorimetric, fluorimetric and electrochemical approaches. Examples of smart wound dressings that integrate controllable drug delivery functions triggered by both endogenous and exogenous stimuli, the all-in-one wound dressing systems capable of real-time monitoring and on-demand treatment, and the major challenges and exciting opportunities of such smart wound dressings in wound management are presented and comprehensively discussed

Controllable promotion of chondrocyte adhesion and growth on PVA hydrogels by controlled release of TGF-beta 1 from porous PLGA microspheres

Poly(vinyl alcohol) (PVA) hydrogels have been candidate materials for cartilage tissue engineering. However, the cell non-adhesive nature of PVA hydrogels has been a limit. In this paper, the cell adhesion and growth on PVA hydrogels were promoted by compositing with transform growth factor-beta 1 (TGF-beta 1) loaded porous poly(D,L-lactide-co-glycolide) (PLGA) microspheres. The porous microspheres were fabricated by a modified double emulsion method with bovine serum albumin (BSA) as porogen. The average pore size of microspheres was manipulated by changing the BSA/PLGA ratio. Such controllable porous structures effectively influenced the encapsulation efficiency (E-encaps) and release profile of TGF-beta 1. By compositing PVA hydrogels with such TGF-beta 1-loaded PLGA microspheres, chondrocyte adhesion and proliferation were significantly promoted in a controllable manner, as confirmed by fluorescent imaging and quantitative CCK-8 assay. That is, the chondrocyte proliferation was favored by using PLGA microspheres with high E-encaps of TGF-beta 1 or by increasing the PLGA microsphere content in the hydrogels. These results demonstrated a facile method to improve the cell adhesion and growth on the intrinsically cell non-adhesive PVA hydrogels, which may find applications in cartilage substitution. (C) 2014 Elsevier B.V. All rights reserved