Sequential deacetylation/self-gelling chitin hydrogels and scaffolds functionalized with fucoidan for enhanced BMP-2 loading and sustained release.

Bone morphogenetic protein 2 (BMP-2) is a potent osteoinductive factor that promotes bone formation. A major obstacle to the clinical application of BMP-2 is its inherent instability and complications caused by its rapid release from implants. Chitin based materials have excellent biocompatibility and mechanical properties, making them ideal for bone tissue engineering applications. In this study, a simple and easy method was developed to spontaneously form deacetylated ß-chitin (DAC-ß-chitin) gels at room temperature through a sequential deacetylation/self-gelation process. The structural transformation of ß-chitin to DAC-ß-chitin leads to the formation of self-gelling DAC-ß-chitin, from which hydrogels and scaffolds were prepared. Gelatin (GLT) accelerated the self-gelation of DAC-ß-chitin and increased the pore size and porosity of the DAC-ß-chitin scaffold. The DAC-ß-chitin scaffolds were then functionalized with a BMP-2-binding sulfate polysaccharide, fucoidan (FD). Compared with ß-chitin scaffolds, FD-functionalized DAC-ß-chitin scaffolds showed higher BMP-2 loading capacity and more sustainable release of BMP-2, and thus had better osteogenic activity for bone regeneration.

Understanding the Meaningful Places for Aging-in-Place: A Human-Centric Approach toward Inter-Domain Design Criteria Consideration in Taiwan.

BACKGROUND: Aging is key to inclusion, and it should be taken into account when designing every place of human activity. However, the implementation of such guidelines often fails the human-centric aspiration as health and design domain interpretation gaps impede the suitable reading and implementation strategies. PURPOSE: This study aimed to understand critical factors in the place-of-aging and to examine the gap in domain interpretation affecting age-friendly housing. METHODS: Using grounded theory as a base, questionnaire interviews were implemented either face-to-face or through an online process by health and design domain experts. Overall, 40 respondents (20 health and 20 design experts) evaluated the key criteria to prioritize according to their value of importance. The factor analysis resulted in the stated deviation, suggesting a necessity to redefine the attributes of the dwelling based on a people, place and process framework. RESULTS: The systemic analysis affirmed the inter-disciplinary gap to enhancing the dwelling provision. The health domain experts consistently ranked the criteria higher or equal than the design domain except for safety and security criteria. Both domains agreed that affordability is a main concern, as elders must be able to afford their dwelling choice. CONCLUSION: The valuable finding of the key criteria in the study is to uphold the value of the urban health resilience implication as the core of this study.

Modification of chitosan nanofibers with CuS and fucoidan for antibacterial and bone tissue engineering applications.

Chitosan (CS) electrospun nanofiber (ENF) membranes were modified with fucoidan (Fu) and CuS NPs through polyelectrolyte complexation and genipin (GP)-involved cross-linking reaction. The formation of Fu/CS complex and cross-linking of CS with GP increased the acid resistance and reduced the swelling rate of CS ENF, while the covalent conjugation of CuS NPs provided CS ENF with durable Fenton-like catalytic activity. The CuS@ENF composite (ENFC) effectively adsorbed H2O2 and near-infrared (NIR) light, enabling it to kill bacteria by photothermal and photocatalytic bactericidal effects. Fu and copper ions were able to release from the ENFC in a pH-dependent manner, and promoted the alkaline phosphatase activity of osteoblast cells and capillary tube formation of endothelial cells. This study provides a new approach to modify CS ENF with antibacterial and osteoblast differentiation activities, which may be available for bone infection prevention and tissue regeneration.

Attenuative Effects of Platelet-Rich Plasma on 30 kDa Fibronectin Fragment-Induced MMP-13 Expression Associated with TLR2 Signaling in Osteoarthritic Chondrocytes and Synovial Fibroblasts.

Proteolytic fragments of fibronectin can have catabolic effects on cartilage, menisci, and synovium. Previous studies have reported that Toll-like receptor (TLR) signaling pathways might be associated with joint inflammation and joint destruction. Platelet-rich plasma (PRP) is increasingly being used to treat a range of joint conditions; however, it has yet to be determined whether PRP influences fibronectin fragment (FN-f) procatabolic activity and TLRs. In this study, human primary culture cells were treated with 30 kDa FN-f with/without PRP co-incubation, and then analyzed using real-time PCR to determine gene expression levels in articular chondrocytes, meniscal fibrochondrocytes, and synovial fibroblasts. Protein levels were evaluated by Western immunoblotting. This study observed an increase in the protein expression of matrix metalloproteinases (MMPs), Toll-like receptor 2 (TLR2), nitric oxide synthase 2 (NOS2), prostaglandin-endoperoxide synthase (PTGS2), and cyclooxygenase 2 (COX2) in articular chondrocytes, meniscal fibrochondrocytes, and synovial fibroblasts following insult with 30 kDa FN-f. Upregulation of these genes was significantly attenuated by PRP treatment. TLR2 and matrix metalloproteinase 13 (MMP-13) were also significantly attenuated by cotreatment with 30 kDa FN-f + PRP + TLR2 inhibitor. PRP treatment was shown to attenuate the 30 kDa FN-f-induced MMP-13 expression associated with the decreased expression of TLR2 in osteoarthritic chondrocytes and synovial fibroblasts. PRP treatment was also shown to attenuate procatabolic activity associated with MMP-13 expression via the TLR2 signaling pathway.

A smart and active film with tunable drug release and color change abilities for detection and inhibition of bacterial growth.

Antimicrobial resistance has become a global issue and thus the development of natural products/biomedical materials composites with antibacterial activities is urgently needed. When acute wounds develop into chronic wounds, the wound environments become alkaline. As long as infections occur, the wound pH further increases, making the wounds difficult to heal. Besides, bacterial growth in poultry, meat, fish and seafood products is usually reflected in a marked increase of pH values. Herein, smart, stimuli responsive self-assembled multilayer and complex film were constructed through the formation of hydrogen bonds and hydrophobic interactions between hydroxypropyl methylcellulose (HPMC) and epigallocatechin-3-gallate (EGCG), thereby greatly reducing the hydrophilicity of HPMC and offering enhanced mechanical strength, superior free radical scavenging capability, and improved water vapor and light barrier properties. The EGCG/HPMC complex film was able to control EGCG release by tuning pH or temperature of the release medium. Furthermore, incorporation of CuS nanoparticles into the film allowed it to triggers EGCG release in an on-demand fashion under near-infrared (NIR) exposure. Bacterial growth in glucose-free nutrient broth medium caused pH to rise (near pH 8.0), leading to transformation of EGCG from phenol type to phenolate ion and then quinone, allowing for spontaneous generation of H2O2 to kill bacteria. The complex films changed their color in response to bacterial growth because EGCG transformed from phenol type to quinone type under alkaline condition. The green synthesized EGCG/HPMC complex films can be used as a colorimetric pH indicator and an antibacterial material for wound dressing and food packaging applications.

Reduction of AHI1 in the serum of Taiwanese with probable Alzheimer's disease.

OBJECTIVE: The development of blood-based biomarkers for early diagnosis and treatment of Alzheimer's disease (AD) is desirable. In AD model mouse brain and neuronal cells, Abelson helper integration site-1 (AHI1) protein is reduced. AHI1 facilitates intracellular amyloid precursor protein (APP) translocation to inhibit amyloidogenic pathology of AD, and thus may be an AD biomarker. METHODS: This study was conducted among 32 AD patients and 54 healthy control (HC) subjects. AHI1-related protein levels from initially collected serum samples in each group were screened using Western blotting. The protein concentrations of AHI1 and amyloid-ß (Aß), peptide(s) derived from APP, from all serum samples were analyzed using ELISA. RESULTS: In AD serum, AHI1 and a large truncated C-terminal APP fragment were significantly reduced. The average concentrations of serum AHI1 and Aß in AD were significantly lower than those in HC. Notably, AHI1 concentration in HC serum was decreased in an age-dependent manner, while it was consistently low in AD serum and had no correlation with Aß or mini-mental state examination score. The receiver operating characteristic analysis on all subjects demonstrated an area under curve (AUC) value of 0.7 for AHI1 on AD diagnosis, while the AUC increased to 0.82 on the subjects younger than 77 years old, suggesting a good diagnostic performance of serum AHI1 for AD especially at relatively young age. CONCLUSION: An early event of AHI1 reduction in the body of AD patients was observed. Serum AHI1 may be valuable for early diagnosis of AD.

Expression of AHI1 Rescues Amyloidogenic Pathology in Alzheimer's Disease Model Cells.

A hallmark of Alzheimer's disease (AD) pathogenesis is the accumulation of extracellular plaques mainly composed of amyloid-ß (Aß) derived from amyloid precursor protein (APP) cleavage. Recent reports suggest that transport of APP in vesicles with huntingtin-associated protein-1 (HAP1) negatively regulates Aß production. In neurons, HAP1 forms a stable complex with Abelson helper integration site-1 (AHI1), in which mutations cause neurodevelopmental and psychiatric disorders. HAP1 and AHI1 interact with tropomyosin receptor kinases (Trks), which are also associated with APP and mediate neurotrophic signaling. In this study, we hypothesize that AHI1 participates in APP trafficking and processing to rescue AD pathology. Indeed, AHI1 was significantly reduced in mouse neuroblastoma N2a cells expressing human Swedish and Indiana APP (designed as AD model cells) and in 3xTg-AD mouse brain. The AD model cells as well as Ahi1-knockdown cells expressing wild-type APP-695 exhibited a significant reduction in viability. In addition, the AD model cells were reduced in neurite outgrowth. APP C-terminal fragment-ß (CTFß) and Aß42 were increased in the AD cell lysates and the culture media, respectively. To investigate the mechanism how AHI1 alters APP activities, we overexpressed human AHI1 in the AD model cells. The results showed that AHI1 interacted with APP physically in mouse brain and transfected N2a cells despite APP genotypes. AHI1 expression facilitated intracellular translocation of APP and inhibited APP amyloidogenic process to reduce the level of APP-CTFß in the total lysates of AD model cells as well as Aß in the culture media. Consequently, AHI1-APP interactions enhanced neurotrophic signaling through Erk activation and led to restored cell survival and differentiation.

Development of Injectable Fucoidan and Biological Macromolecules Hybrid Hydrogels for Intra-Articular Delivery of Platelet-Rich Plasma.

Platelet-rich plasma (PRP) is rich in growth factors and has commonly been utilized in the repair and regeneration of damaged articular cartilage. However, the major drawbacks of direct PRP injection are unstable biological fixation and fast or burst release of growth factors. Fucoidan is a heparinoid compound that can bind growth factors to control their release rate. Furthermore, fucoidan can reduce arthritis through suppressing inflammatory responses and thus it has been reported to prevent the progression of osteoarthritis, promote bone regeneration and accelerate healing of cartilage injury. Injectable hydrogels can be used to deliver cells and growth factors for an alternative, less invasive treatment of cartilage defects. In this study, hyaluronic acid (HA) and fucoidan (FD) was blended with gelatin (GLT) and the GLT/HA/FD hybrid was further cross-linked with genipin (GP) to prepare injectable GP-GLT/HA/FD hydrogels. The gelation rate was affected by the GP, GLT, HA and FD concentrations, as well as the pH values. The addition of HA and FD to GLT networks improved the mechanical strength of the hydrogels and facilitated the sustained release of PRP growth factors. The GP-GLT/HA/FD hydrogel showed adequate injectability, shape-persistent property and strong adhesive ability, and was more resistant to enzymatic degradation. The PRP-loaded GP-GLT/HA/FD hydrogel promoted cartilage regeneration in rabbits, which may lead to an advanced PRP therapy for enhancing cartilage repair.

Development of genipin-crosslinked and fucoidan-adsorbed nano-hydroxyapatite/hydroxypropyl chitosan composite scaffolds for bone tissue engineering.

Hydroxypropyl chitosan (HPCS) has recently attracted increasing attention in biomedical applications because it has enhanced water solubility, excellent biocompatibility, and better antioxidant and antibacterial activities compared with chitosan. However, HPCS doesn't meet the mechanical strength requirement in bone tissue engineering and is not suitable for cell adhesion and growth because of its hydrophilic nature and low crystallinity. In this study, nano-scaled hydroxyapatite (n-HA) and HPCS were synthesized, respectively, and then n-HA/HPCS nanocomposite scaffolds were developed by incorporating n-HA into HPCS matrix accompanied with crosslinking of HPCS by a naturally occurring compound, genipin (GP), which in turn greatly altered the hydrophilicity and mechanical properties. The nanocomposite scaffolds showed an open structure with interconnected pores and a rough morphology with n-HA inserted in the GP-crosslinked HPCS matrix. The porosity, swelling capacity, compressive strength, fluorescence emission and degradation rate can be regulated by varying GP concentrations and n-HA contents. An osteoconductive and osteogenic marine algae polysaccharide, fucoidan, was further adsorbed to the composite scaffolds via electrostatic interactions. Incorporation of n-HA and adsorption of FD into the composite scaffolds increased ALP activity in 7F2 osteoblast cells and promoted their mineralization. The FD-adsorbed n-HA/HPCS composite scaffolds can be a potential biomaterial for BTE applications.

A novel injectable in situ forming gel based on carboxymethyl hexanoyl chitosan/hyaluronic acid polymer blending for sustained release of berberine.

An in situ forming gel based on simply blending carboxymethyl hexanoyl chitosan (CHC) with low molecular weight hyaluronic acid (LMW HA) was developed, without needing cross-linking, photopolymerization or thermal treatments. The CHC/LMW HA blends formed nanoparticles and then rapidly transformed into supermolecular hydrogels under stirring. The gel formation mechanism was examined by Förster resonance energy transfer (FRET). The gels were injectable, cytocompatible and biodegradable, and showed shape-persistent behavior and adhesive property. Berberine, an anti-apoptotic and anti-arthritis naturally occurring compound, was encapsulated within the CHC/LMW HA gels. The gels demonstrated a pH-responsive characteristic which were able to release berberine in a sustained manner at pH 6.0 (simulating inflamed arthritic articular cartilage) and the degradation rates were accelerated at pH 7.4 (simulating healed normal tissue). The berberine-loaded gels effectively protected chondrocytes against sodium nitroprusside-induced apoptosis. The gels may be potentially useful as an injectable system for intra-articular drug delivery and cartilage tissue engineering.

Development of nanocomposite scaffolds based on biomineralization of N,O-carboxymethyl chitosan/fucoidan conjugates for bone tissue engineering.

Bone tissue engineering holds great promise and clinical efficacy for the regeneration of bone defects. In this study, an amphoteric N,O-carboxymethyl chitosan (NOCC) and fucoidan (FD) were covalently cross-linked via an amidation reaction to synthesize NOCC/FD composite hydrogels. The hydrogels were lyophilized and then three-dimensional scaffolds with interconnected macropores were obtained. To enhance the mechanical properties and osteogenic activity, the NOCC/FD scaffolds were biomineralized for the growth of hydroxyapatite crystals. A comparative assessment of the structures, morphologies, and physical properties of the original and mineralized scaffolds were performed by SEM, EDS, X-ray diffraction and FT-IR analysis. FD regulated the growth of hydroxyapatite nanocrystallites (n-HAp) and thus the NOCC/FD scaffolds showed better mineralization efficiency than NOCC scaffolds. The compressive strength of the scaffolds was greatly enhanced after mineralization with n-HAp. The n-HAp/NOCC/FD scaffolds enhanced the proliferation, ALP activity, and mineralization of osteoblast cells more strongly than the original and mineralized NOCC scaffolds. Hence, the n-HAp-mineralized NOCC/FD scaffolds may prove to be an excellent and versatile scaffold for bone tissue engineering.

The Association Between Long-Term Bisphosphonate Use and the Risk of Fracture Among Women Aged 50 or Older with Osteoporosis.

BACKGROUND: Osteoporosis is a prevalent disease, and bisphosphonates can effectively reduce the risk of osteoporotic fractures. However, the association between the length of the medication treatment and the risk of fractures remains unclear. The purpose of this study was to evaluate the association between long-term bisphosphonate use (treatment duration ≥5 years) and the risk of fractures among women with osteoporosis aged 50 or older. MATERIALS AND METHODS: We conducted a retrospective cohort study by using the 2001-2011 National Health Insurance Research Database in Taiwan. We included women who were 50 years or older, who had a diagnosis of osteoporosis, and who were newly initiating oral bisphosphonates between January 1, 2002 and December 31, 2003. The index date was the date of the first dispensing of oral bisphosphonate during the enrollment period. Women were considered to be using bisphosphonates until they had a gap in supply of more than 3 months. We classified bisphosphonate use as long term (≥5 years) and regular (<5 years) based on its length of use. The dependent variable was the time to the first observed clinical fracture. Cox-proportional hazard regression models were used to evaluate the association between long-term bisphosphonate use and the risk of fractures. RESULTS: The study included 1342 women with a mean age of 71 years. Of them, 83 (6.2%) were long-term bisphosphonate users. A total of 185 (13.8%) had a fracture. After adjustments, long-term bisphosphonate use was not associated with a lower risk of fractures than was regular bisphosphonate use (adjusted hazard ratio: 1.49, 95% CI: 0.91-2.45). CONCLUSION: This study found no evidence of a lower risk of fractures to be associated with long-term bisphosphonate use among women aged 50 or older with osteoporosis in Taiwan. Orthopedists as well as other healthcare providers should be aware of the limited benefits of long-term bisphosphonate use.

Medial retinacular flap advancement and arthroscopic lateral release for symptomatic chronic patellar lateral subluxation with tilting.

PURPOSE: The purpose of this study was to investigate outcomes of surgical treatment in patients with symptomatic chronic patellar lateral subluxation with tilting. METHODS: Thirty-two patients (38 knees) underwent arthroscopic lateral release and mini-open advancement of medial retinacular flap for the treatment of symptomatic chronic patellar lateral subluxation with tilting with a mean follow-up of 52.0±11.4 months. The mean age at surgery was 24.7±8.8 years, and the duration of symptoms was 4.8±4.1 years. The patellofemoral function of the knee was evaluated before surgery and at the clinical follow-up using the Kujala functional score. RESULTS: Thirty-six knees (95%) showed excellent or good results after surgery. Two knees with grade IV chondromalacia of the patella had fair results with persistent apprehension signs and persistent pain. The Kujala patellofemoral functional scores improved by an average of 20.9 points from a mean value of 71.8±12.1 preoperatively to 92.7±10.7 postoperatively (P<0.01). Radiographically, there were significant improvements in congruence angle from 23.4°±7.9° preoperatively to -7.2°±6.4° postoperatively (P<0.01) and in the lateral patellofemoral angle from -8.6°±6.8° preoperatively to 6.3°±4.2° postoperatively (P<0.01). CONCLUSIONS: Medial retinacular flap advancement and arthroscopic lateral release offer a promising treatment for symptomatic chronic patellar lateral subluxation and tilt without frank traumatic episode. LEVEL OF EVIDENCE: Retrospective study, Level IV.

Injectable hyaluronic-acid-doxycycline hydrogel therapy in experimental rabbit osteoarthritis.

BACKGROUND: Osteoarthritis (OA) is a common joint disease that causes disabilities in elderly adults. However, few long-lasting pharmacotherapeutic agents with low side effects have been developed to treat OA. We evaluated the therapeutic effects of intra-articular injections of hydrogels containing hyaluronic acid (HA) and doxycycline (DOX) in a rabbit OA model. RESULTS: Thirteen week old New Zealand White rabbits undergone a partial meniscectomy and unilateral fibular ligament transection were administered with either normal saline (NT), HA, DOX or HA-DOX hydrogels on day 0, 3, 6, 9 and 12; animals were also examined the pain assessment in every three days. The joint samples were taken at day 14 post-surgery for further histopathological evaluation. The degree of pain was significantly attenuated after day 7 post-treatment with both HA and HA-DOX hydrogels. In macroscopic appearance, HA-DOX hydrogel group showed a smoother cartilage surface, no or minimal signs of ulceration, smaller osteophytes, and less fissure formation in compare to HA or DOX treatment alone. In the areas with slight OA changes, HA-DOX hydrogel group exhibited normal distribution of chondrocytes, indicating the existence of cartilage regeneration. In addition, HA-DOX hydrogels also ameliorated the progression of OA by protecting the injury of articular cartilage layer and restoring the elastoviscosity. CONCLUSION: Overall, from both macroscopic and microscopic data of this study indicate the injectable HA-DOX hydrogels presented as a long-lasting pharmacotherapeutic agent to apply for OA therapy.

Rapid-onset sildenafil nasal spray carried by microemulsion systems: in vitro evaluation and in vivo pharmacokinetic studies in rabbits.

An oleic acid-based microemulsion system with a member of the Tween series or Cremophor EL as the surfactant and a short-chain alcohol as the cosolvent was developed for rapid-onset intranasal delivery of sildenafil. The phase behaviour and solubilization capacity of the microemulsion system were characterized, and nasal absorption of sildenafil from the microemulsion formulations was investigated in rabbits. Sildenafil displayed a high solubility of 124 mg/mL in the microemulsion consisting of 40% oleic acid, 10% H(2)O, and 50% Tween 80:ethanol (EA) (at a 1:4 weight ratio). Nasal absorption of sildenafil from this microemulsion was found to be fairly rapid. With a 10-mg dose, the onset of action was arrived instantly following intranasal administration and the duration was over 3 h using an in vivo rabbit studies. In addition, nasal ciliotoxicity studies were carried out using in vivo rat nasal mucosa model and showed no ciliotoxicity. Therefore, the prepared systems are no serious nasal ciliotoxicity for intranasal administration. The microemulsion system composed of oleic acid, Tween 80, EA, and water may be a practical approach for the rapid-onset delivery of sildenafil for the treatment of erectile dysfunction.

Disease-modifying effects of glucosamine HCl involving regulation of metalloproteinases and chemokines activated by interleukin-1beta in human primary synovial fibroblasts.

The purpose of this study was to investigate the possible involvement of synovium in cartilage destruction in osteoarthritis (OA) patients. Using human primary synovial fibroblasts (HPSFs), we examined the effects of glucosamine (GLN) on the regulation of the expression of matrix metalloproteinases (MMP-1, -2, and -13) and chemokines (IL-8, MCP-1, and RANTES) as well as the involvement of MAPK signal pathways (JNK, ERK, and p-38) and the transcription factor of NF-kappaB on the present or absence of interleukin (IL)-1beta. Our experiments showed that protein production and mRNA expressions of MMP-1, MMP-3, MMP-13, IL-8, MCP-1, and RANTES were downregulated by treatment with glucosamine in HPSFs. The results further showed that GLN could inhibit IkappaBalpha phosphorylation and IkappaBalpha degradation leading to inhibition of the translocation of NF-kappaB to nuclei. However, GLN upregulated MAPKs pathways in HPSFs cells with or without IL-1beta. The results suggest that the inhibition of MMP-1, -3, and -13 expressions as well as IL-8, MCP-1, and RANTES productions by GLN might mediate suppression of NF-kappaB signal pathways, and HPSFs seem to have a potential functions as an alternative source of MMPs and chemokines for inducing the degradation of cartilage in OA.