Background: High mobility group proteins 1 and 2 (HMGB1 and HMGB2) are 80% conserved in amino acid sequence. The function of HMGB1 in inflammation and fibrosis has been extensively characterized. However, an unaddressed central question is the role of HMGB2 on liver fibrosis.
View Article and Find Full Text PDFAlthough bone tissue allografts and autografts aremoften used as a regenerative tissue during the bone healing, their availability, donor site morbidity, and immune response to grafted tissue are limiting factors their more common usage. Tissue engineered implants, such as acellular or cellular polymeric structures, can be an alternative solution. A variety of scaffold fabrication techniques including electrospinning, particulate leaching, particle sintering, and more recently 3D printing have been used to create scaffolds with interconnected pores and mechanical properties for tissue regeneration.
View Article and Find Full Text PDFTendon injuries are common and account for up to 50% of musculoskeletal injuries in the United States. The poor healing nature of the tendon is attributed to poor vascularization and cellular composition. In the absence of FDA-approved growth factors for tendon repair, engineering strategies using bioactive factors, donor cells, and delivery matrices to promote tendon repair and regeneration are being explored.
View Article and Find Full Text PDFPeripheral nerve injuries account for roughly 3% of all trauma patients with over 900,000 repair procedures annually in the US. Of all extremity peripheral nerve injuries, 51% require nerve repair with a transected gap. The current gold-standard treatment for peripheral nerve injuries, autograft repair, has several shortcomings.
View Article and Find Full Text PDFCorrection for 'Growing a backbone - functional biomaterials and structures for intervertebral disc (IVD) repair and regeneration: challenges, innovations, and future directions' by Matthew D. Harmon et al., Biomater.
View Article and Find Full Text PDFElectrical stimulation (ES) is predominantly used as a physical therapy modality to promote tissue healing and functional recovery. Research efforts in both laboratory and clinical settings have shown the beneficial effects of this technique for the repair and regeneration of damaged tissues, which include muscle, bone, skin, nerve, tendons, and ligaments. The collective findings of these studies suggest ES enhances cell proliferation, extracellular matrix (ECM) production, secretion of several cytokines, and vasculature development leading to better tissue regeneration in multiple tissues.
View Article and Find Full Text PDFEngineered soft tissue products-both tendon and ligament-have gained tremendous interest in regenerative medicine as alternatives to autograft and allograft treatments due to their potential to overcome limitations such as pain and donor site morbidity. Tendon engineered grafts have focused on the replication of native tendon tissue composition and architecture in the form of scaffolds using synthetic or natural biomaterials seeded with cells and factors. However, these approaches suffer due to static culture environments that fail to mimic the dynamic tissue environment and mechanical forces required to promote tenogenic differentiation of cultured cells.
View Article and Find Full Text PDFBack pain and associated maladies can account for an immense amount of healthcare cost and loss of productivity in the workplace. In particular, spine related injuries in the US affect upwards of 5.7 million people each year.
View Article and Find Full Text PDFArtificial nerve guidance conduits (NGCs) are being investigated as an alternative to autografts, since autografts are limited in supply. A polycaprolactone (PCL)-based spiral NGC with crosslinked laminin on aligned nanofibers was evaluated in vivo post a successful in vitro assessment. PC-12 cell assays confirmed that the aligned nanofibers functionalized with laminin were able to guide and enhance neurite outgrowth.
View Article and Find Full Text PDFPeripheral nerve injuries can be extremely debilitating, resulting in sensory and motor loss-of-function. Endogenous repair is limited to non-severe injuries in which transection of nerves necessitates surgical intervention. Traditional treatment approaches include the use of biological grafts and alternative engineering approaches have made progress.
View Article and Find Full Text PDFThe current status of skin tissue equivalents that have emerged as relevant tools in commercial and therapeutic product development applications is reviewed. Due to the rise of animal welfare concerns, numerous companies have designed skin model alternatives to assess the efficacy of pharmaceutical, skincare, and cosmetic products in an in vitro setting, decreasing the dependency on such methods. Skin models have also made an impact in determining the root causes of skin diseases.
View Article and Find Full Text PDFThis Article reports the fabrication and characterization of composite micro-nanostructured spiral scaffolds functionalized with nanofibers and hydroxyapatite (HA) for bone regeneration. The spiral poly(lactic acid--glycolic acid) (PLGA) porous microstructure was coated with sparsely spaced PLGA nanofibers and HA to enhance surface area and bioactivity. Polyelectrolyte-based HA coating in a layer-by-layer (LBL) fashion allowed 10-70 M Ca/mm incorporation.
View Article and Find Full Text PDFRicinoleic acid (RA) has potential to promote wound healing because of its analgesic and anti-inflammatory properties. This study investigates the synthesis and characterization of RA liposomes infused in a hydrogel for topical application. Lecithin liposomes containing RA were prepared and incorporated into a chitosan solution and were subsequently cross-linked with dialdehyde β-cyclodextrin (Di-β-CD).
View Article and Find Full Text PDFComplex craniofacial surgeries of damaged tissues have several limitations, which present complications and challenges when trying to replicate facial function and structure. Traditional treatment techniques have shown suitable nerve function regeneration with various drawbacks. As technology continues to advance, new methods have been explored in order to regenerate damaged nerves in an effort to more efficiently and effectively regain original function and structure.
View Article and Find Full Text PDFPeripheral nerve injury accounts for roughly 2.8% of all trauma patients with an annual cost of 7 billion USD in the U.S.
View Article and Find Full Text PDFStem cell strategies and the use of electrical stimulation (ES) represent promising new frontiers for peripheral nerve regeneration. Composite matrices were fabricated by coating electrospun polycaprolactone/cellulose acetate micro-nanofibers with chitosan and ionically conductive (IC) polymers including, sulfonated polyaniline, and lignin sulfonate. These composite matrices were characterized for surface morphology, coating uniformity, ionic conductivity, and mechanical strength to explore as scaffold materials for nerve regeneration in conjunction with ES.
View Article and Find Full Text PDF3D printing, or rapid prototyping, is a fabrication technique that is used for various engineering applications with advantages such as mass production and fine tuning of spatial-dimensional properties. Recently, this fabrication method has been adopted for tissue engineering applications due to its ability to finely tune porosity and create precise, uniform, and repeatable structures. This review aims to introduce 3D printing applications in soft tissue engineering and regenerative medicine including state-of-the-art scaffolds and key future challenges.
View Article and Find Full Text PDFFor many years, the avascular nature of cartilage tissue has posed a clinical challenge for replacement, repair, and reconstruction of damaged cartilage within the human body. Injuries to cartilage and osteochondral tissues can be due to osteoarthritis, sports, aggressive cancers, and repetitive stresses and inflammation on wearing tissue. Due to its limited capacity for regeneration or repair, there is a need for suitable material systems which can recapitulate the function of the native osteochondral tissue physically, mechanically, histologically, and biologically.
View Article and Find Full Text PDFDevelopment of injectable, long-lasting, contraceptive drug delivery formulations and implants are highly desired to avoid unplanned pregnancies while improving patient compliance and reducing adverse side effects and treatment costs. The present study reports on the fabrication and characterization of two levonorgestrel (LNG) microsphere injectable formulations. Poly(ε-caprolactone) (PCL) with 12.
View Article and Find Full Text PDFCell level inflammatory signalling is a combination of initiation at cell membrane receptors and modulation by cytoplasmic regulatory proteins. For keratinocytes, the predominant cell type in the epidermis, this would include toll-like receptors (TLR) and cytoplasmic proteins that propagate or dampen post-receptor signalling. We previously reported that increased levels of tumor necrosis factor α induced protein 3-interacting protein 1 (TNIP1) in HaCaT keratinocytes leads to decreased expression of stress response and inflammation-associated genes.
View Article and Find Full Text PDFA variety of engineered scaffolds have been created for tissue engineering using polymers, ceramics and their composites. Biomimicry has been adopted for majority of the three-dimensional (3D) scaffold design both in terms of physicochemical properties, as well as bioactivity for superior tissue regeneration. Scaffolds fabricated via salt leaching, particle sintering, hydrogels and lithography have been successful in promoting cell growth and tissue regeneration .
View Article and Find Full Text PDFActivation of hepatic stellate cells (HSCs) is critical for liver fibrosis development. Previously, we showed that astaxanthin (ASTX), a xanthophyll carotenoid, has antifibrogenic effects in LX-2 cells, a human HSC cell line. We sought to determine the effect of ASTX on HSC activation, and to identify molecular mediators that are critically involved in the processes.
View Article and Find Full Text PDFA variety of rodent models of hepatoprotection have been developed in which tolerance to acetaminophen-induced hepatotoxicity occurs. Autoprotection/heteroprotection is a phenomenon where prior exposure to a mildly toxic dose of toxicant confers protection against a subsequently administered higher dose of the same toxicant (as in the case of autoprotection) or to a different toxicant (referred to as heteroprotection). Multiple mechanisms regulate this adaptive response, including hepatocellular proliferation, proteostasis, enhanced expression of cytoprotective genes, and altered tissue immune response.
View Article and Find Full Text PDFAnnu Rev Pharmacol Toxicol
September 2016
Nuclear receptors (NR) are ligand-modulated transcription factors that play diverse roles in cell differentiation, development, proliferation, and metabolism and are associated with numerous liver pathologies such as cancer, steatosis, inflammation, fibrosis, cholestasis, and xenobiotic/drug-induced liver injury. The network of target proteins associated with NRs is extremely complex, comprising coregulators, small noncoding microRNAs, and long noncoding RNAs. The importance of NRs as targets of liver disease is exemplified by the number of NR ligands that are currently used in the clinics or in clinical trials with promising results.
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