A Bionic Thermosensitive Sustainable Delivery System for Reversing the Progression of Osteoarthritis by Remodeling the Joint Homeostasis.

Although the pathogenesis of osteoarthritis (OA) is unclear, inflammatory cytokines are related to its occurrence. However, few studies focused on the therapeutic strategies of regulating joint homeostasis by simultaneously remodeling the anti-inflammatory and immunomodulatory microenvironments. Fibroblast growth factor 18 (FGF18) is the only disease-modifying OA drug (DMOAD) with a potent ability and high efficiency in maintaining the phenotype of chondrocytes within cell culture models. However, its potential role in the immune microenvironment remains unknown. Besides, information on an optimal carrier, whose interface and chondral-biomimetic microenvironment mimic the native articular tissue, is still lacking, which substantially limits the clinical efficacy of FGF18. Herein, to simulate the cartilage matrix, chondroitin sulfate (ChS)-based nanoparticles (NPs) are integrated into poly(D, L-lactide)-poly(ethylene glycol)-poly(D, L-lactide) (PLEL) hydrogels to develop a bionic thermosensitive sustainable delivery system. Electrostatically self-assembled ChS and ε-poly-l-lysine (EPL) NPs are prepared for the bioencapsulation of FGF18. This bionic delivery system suppressed the inflammatory response in interleukin-1ß (IL-1ß)-mediated chondrocytes, promoted macrophage M2 polarization, and inhibited M1 polarization, thereby ameliorating cartilage degeneration and synovitis in OA. Thus, the ChS-based hydrogel system offers a potential strategy to regulate the chondrocyte-macrophage crosstalk, thus re-establishing the anti-inflammatory and immunomodulatory microenvironment for OA therapy.

Laponite intercalated biomimetic multilayer coating prevents glucocorticoids induced orthopedic implant failure.

Implant failure, which is commonly associated with failure of osseointegration and peri-implant infection, is a severe complication of orthopedic surgery. In particular, the survival rate of implants is significantly decreased in patients using long-term glucocorticoids (GCs). However, the exact molecular mechanism underlying GCs-induced implant loosening, as well as preventive strategies for these patients, is unclear. To address this problem, we performed RNA-sequencing and found that WNT16 was correlated with GCs-induced osteopenia (LogFC = -5.17, p ＜ 0.01). Inspired by the concept of "organic-inorganic" hybrid, we theorized to introduce a bioactive two-dimensional nanosheet into a layer-by-layer (LbL) self-assembly coating to construct a customized implant that targets WNT16. After screening commercially available nanosheets, laponite (LAP) was identified as a cost-effective rescuer for GCs-induced WNT16 inhibition, which was then intercalated into LbL deposition system consisting of quaternized chitosan (QCS) and hyaluronic acid (HA). The hybrid coating (QCS/HA/LAP) showed micrometer thickness and improved hydrophilicity and interface roughness. Furthermore, QCS/HA/LAP coated polyetheretherketone (PEEK) implant enhanced cell viability, adhesion, and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs), and promoted osteointegration of PEEK in GCs-treated rats by targeting the WNT16/ß-catenin axis. The assembled QCS has proven antibacterial properties, and the hybrid coating exerted potent detrimental effects against methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli), both in vitro and in vivo. Taken together, these results suggest that QCS/HA/LAP coating has great potential for use in implants customization, and has synergistic pro-osteogenic and antibacterial effects that help prevent implant failure in GCs-treated patients.

Autologous Costal Cartilage Grafting for a Large Osteochondral Lesion of the Femoral Head: A 1-Year Single-Arm Study with 2 Additional Years of Follow-up.

BACKGROUND: There is currently no ideal treatment for osteochondral lesions of the femoral head (OLFH) in young patients. METHODS: We performed a 1-year single-arm study and 2 additional years of follow-up of patients with a large (defined as >3 cm 2 ) OLFH treated with insertion of autologous costal cartilage graft (ACCG) to restore femoral head congruity after lesion debridement. Twenty patients ≤40 years old who had substantial hip pain and/or dysfunction after nonoperative treatment were enrolled at a single center. The primary outcome was the change in Harris hip score (HHS) from baseline to 12 months postoperatively. Secondary outcomes included the EuroQol visual analogue scale (EQ VAS), hip joint space width, subchondral integrity on computed tomography scanning, repair tissue status evaluated with the Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) score, and evaluation of cartilage biochemistry by delayed gadolinium-enhanced magnetic resonance imaging of cartilage (dGEMRIC) and T2 mapping. RESULTS: All 20 enrolled patients (31.02 ± 7.19 years old, 8 female and 12 male) completed the initial study and the 2 years of additional follow-up. The HHS improved from 61.89 ± 6.47 at baseline to 89.23 ± 2.62 at 12 months and 94.79 ± 2.72 at 36 months. The EQ VAS increased by 17.00 ± 8.77 at 12 months and by 21.70 ± 7.99 at 36 months (p < 0.001 for both). Complete integration of the ACCG with the bone was observed by 12 months in all 20 patients. The median MOCART score was 85 (interquartile range [IQR], 75 to 95) at 12 months and 75 (IQR, 65 to 85) at the last follow-up (range, 24 to 38 months). The ACCG demonstrated magnetic resonance properties very similar to hyaline cartilage; the median ratio between the relaxation times of the ACCG and recipient cartilage was 0.95 (IQR, 0.90 to 0.99) at 12 months and 0.97 (IQR, 0.92 to 1.00) at the last follow-up. CONCLUSIONS: ACCG is a feasible method for improving hip function and quality of life for at least 3 years in young patients who were unsatisfied with nonoperative treatment of an OLFH. Promising long-term outcomes may be possible because of the good integration between the recipient femoral head and the implanted ACCG. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Decellularized tilapia fish skin: A novel candidate for tendon tissue engineering.

The poor regenerative ability of injured tendon tissues remains a clinical challenge. However, decellularized extracellular matrix (ECM) combined with stem cells shows promise. In contrast to bovine and porcine ECM, marine-derived decellularized ECM has several advantages; it is easily obtained, poses less biological risk, and is not contraindicated on religious grounds. This study successfully fabricated decellularized tilapia fish skin (DTFS) with copious preserved collagen fibers and natural pore structures. The outer layer is smooth and dense, while the inner layer has a soft structure with a rough surface. After crosslinking with 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC) and N-hydroxysuccinimide (NHS), crosslinked DTFS (C-DTFS) showed improved mechanics in dry and wet conditions. In vitro, the leach liquor of crosslinked DTFS showed no cytotoxicity and promoted migration and tenonic differentiation of tendon-derived stem cells (TDSCs). Meanwhile, TDSCs seeded in the inner surface of DTFS maintained viability, differentiated, and exhibited spreading. Furthermore, cell-seeded scaffolds guided the regeneration of tendon tissue in a rat Achilles tendon defect model. Our results suggest that DTFS combined with TDSCs is a novel and promising therapeutic option for tendon tissue engineering.

Lithium chloride prevents glucocorticoid-induced osteonecrosis of femoral heads and strengthens mesenchymal stem cell activity in rats.

BACKGROUND: Accumulating evidence suggests that lithium influences mesenchymal stem cell (MSC) proliferation and osteogenic differentiation. As decreased bone formation in femoral heads is induced by glucocorticoids (GCs), we hypothesized that lithium has a protective effect on GC-induced osteonecrosis of femoral heads (ONFH). METHODS: A rat ONFH model was induced by methylprednisolone (MP) and the effect of lithium chloride on the models was evaluated. Micro-computed tomography (CT)-based angiography and bone scanning were performed to analyze the vessels and bone structure in the femoral heads. Hematoxylin and eosin and immunohistochemical staining were performed to evaluate the trabecular structure and osteocalcin (OCN) expression, respectively. Bone marrow-derived MSCs were isolated from the models, and their proliferative and osteogenic ability was evaluated. Western blotting and quantitative real-time polymerase chain reaction were performed to detect osteogenic-related proteins including Runx2, alkaline phosphatase, and Collagen I. RESULTS: Micro-CT analysis showed a high degree of osteonecrotic changes in the rats that received only MP injection. Treatment with lithium reduced this significantly in rats that received lithium (MP + Li group); while 18/20 of the femoral heads in the MP showed severe osteonecrosis, only 5/20 in the MP + Li showed mild osteonecrotic changes. The MP + Li group also displayed a higher vessel volume than the MP group (0.2193 mm3vs. 0.0811 mm3, P < 0.05), shown by micro-CT-based angiography. Furthermore, histological analysis showed better trabecular structures and more OCN expression in the femoral heads of the MP + Li group compared with the MP group. The ex vivo investigation indicated higher proliferative and osteogenic ability and upregulated osteogenic-related proteins in MSCs extracted from rats in the MP + Li group than that in the MP group. CONCLUSIONS: We concluded that lithium chloride has a significant protective effect on GC-induced ONFH in rats and that lithium also enhances MSC proliferation and osteogenic differentiation in rats after GC administration.

Well-dispersed platelet lysate entrapped nanoparticles incorporate with injectable PDLLA-PEG-PDLLA triblock for preferable cartilage engineering application.

Platelet lysate (PL) as a cost-effective cocktail of growth factors is an emerging ingredient in regenerative medicine, especially in cartilage tissue engineering. However, most studies fail to pay attention to PL's intrinsic characteristics and incorporate it directly with scaffolds or hydrogels by simple mixture. Currently, the particle size distribution of PL was determined to be scattered. Directly introducing PL into a thermosensitive poly(d,l-lactide)-poly(ethylene glycol)-poly(d,l-lactide) (PLEL) hydrogel disturbed its sol-gel transition. Electrostatic self-assembly heparin (Hep) and ε-poly-l-lysine (EPL) nanoparticles (NPs) were fabricated to improve the dispersity of PL. Such PL-NPs-incorporated PLEL gels retained the initial gelling capacity and showed a long-term PL-releasing ability. Moreover, the PL-loaded composite hydrogels inhibited the inflammatory response and dedifferentiation of IL-1ß-induced chondrocytes. For in vivo applications, the PLEL@PL-NPs system ameliorated the early cartilage degeneration and promoted cartilage repair in the late stage of osteoarthritis. RNA sequencing analysis indicated that PL's protective effects might be associated with modulating hyaluronan synthase 1 (HAS-1) expression. Taken together, these results suggest that well-dispersed PL by Hep/EPL NPs is a preferable approach for its incorporation into hydrogels and the constructed PLEL@PL-NPs system is a promising cell-free and stepwise treatment option for cartilage tissue engineering.

A free-standing multilayer film as a novel delivery carrier of platelet lysates for potential wound-dressing applications.

Great efforts have been made to develop suitable bioactive constructs that release growth factors (GFs) in a controlled manner for tissue-regeneration applications. Platelet lysates (PLs) are an affordable source of multiple GFs and other proteins, and show great potential in the wound-healing process. Herein, poly-l-lysine (PLL) and hyaluronic acid (HA) were applied to build free-standing polyelectrolyte multilayer films (PEMs) using the PH-amplified layer-by-layer self-assembly method. Molecular simulations were performed, which showed that in the end layer of PEMs, HA was more attractive to PLs than was PLL. The HA/PLL films constructed with or without 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride (EDC) cross-linking both absorbed PLs successfully, exhibiting high hydrophilicity and GF absorptivity. The release profile of the EDC30 film lasted up to 2 weeks, and PL-loaded films supported cell proliferation, adhesion, migration, and angiogenesis in vitro. Moreover, due to sustained delivery of PLs, the membranes (especially the crosslinked film) helped to promote granulation-tissue formation, collagen deposition, and neovascularization in the region of the defect, resulting in rapid re-epithelialization and regeneration of skin. Mechanistically, the beneficial effects of a PL-loaded PEM coating might be related to activation of the hypoxia-inducible factor-1(Hif-1α)/vascular endothelial growth factor (VEGF) axis. As an off-the-shelf and cell-free treatment option, these biomimetic multilayers have great potential for use in the fabrication of devices that allow stable incorporation of PLs, thereby exerting synergistic effects for efficient wound healing.

A decellularized scaffold derived from squid cranial cartilage for use in cartilage tissue engineering.

Decellularized cartilage scaffold (DCS) is an emerging substitute for cartilage defect application. However, it is hard to preserve an intact structure of such scaffolds derived from terrestrial animals, because of their dense and compact constitution. In contrast, squid (Dosidicus gigas) cranial cartilage, which possesses a relatively loose structure, could be easily decellularized using mild conditions and it retains the original microstructures of extracellular matrix (ECM). Herein, decellularized squid cranial cartilage scaffold (DSCS) was fabricated successfully after substantially removing the cells, which contained abundant ECM components (proteoglycans and type II collagen). Microscopic structure results showed that the DSCS possesses a relatively smooth and dense surface with a favorable interconnected inner porous structure for cell growth. DSCS exhibited excellent biomechanics and hydrophilicity. In vitro experiments indicated that the scaffold extracts were not toxic to cells, and were amenable to chondrocyte migration. Meanwhile, chondrocytes seeded in DSCS could maintain a favorable viability and present a spreading morphology. Furthermore, the in vivo experiments revealed that both cell-free scaffold and cell-laden scaffold exert promotive effects for the regeneration of cartilage in a full-thickness rabbit cartilage defect model. Taken together, these results suggested that DSCS presents a novel and promising cell-free therapeutic choice for cartilage tissue engineering.

Exosomes derived from human platelet-rich plasma prevent apoptosis induced by glucocorticoid-associated endoplasmic reticulum stress in rat osteonecrosis of the femoral head via the Akt/Bad/Bcl-2 signal pathway.

An excess of glucocorticoids (GCs) is reported to be one of the most common causes of osteonecrosis of the femoral head (ONFH). In addition, GCs can induce bone cell apoptosis through modulating endoplasmic reticulum (ER) stress. Among the three main signal pathways in ER stress, the PERK (protein kinase RNA-like ER kinase)/CHOP (CCAAT-enhancer-binding protein homologous protein) pathway has been considered to be closely associated with apoptosis. Platelet-rich plasma (PRP) has been referred to as a concentration of growth factors and the exosomes derived from PRP (PRP-Exos) have a similar effect to their parent material. The enriched growth factors can be encapsulated into PRP-Exos and activate Akt and Erk pathways to promote angiogenesis. Activation of the Akt pathway may promote the expression of anti-apoptotic proteins like Bcl-2, while CHOP can inhibit B-cell lymphoma 2 (Bcl-2) expression to increase the level of cleaved caspase-3 and lead to cell death. Consequently, we hypothesized that PRP-Exos prevent apoptosis induced by glucocorticoid-associated ER stress in rat ONFH via the Akt/Bad/Bcl-2 signal pathway. To verify this hypothesis, a dexamethasone (DEX)-treated in vitro cell model and methylprednisolone (MPS)-treated in vivo rat model were adopted. Characterization of PRP-Exos, and effects of PRP-Exos on proliferation, apoptosis, angiogenesis, and osteogenesis of cells treated with GCs in vitro and in vivo were examined. Furthermore, the mechanism by which PRP-Exos rescue the GC-induced apoptosis through the Akt/Bad/Bcl-2 pathway was also investigated. The results indicate that PRP-Exos have the capability to prevent GC-induced apoptosis in a rat model of ONFH by promoting Bcl-2 expression via the Akt/Bad/Bcl-2 signal pathway under ER stress.

Incidence and outcome of adult in-hospital cardiac arrest in Beijing, China.

OBJECTIVE: To assess the incidence and outcome of in-hospital cardiac arrests (IHCAs) in Beijing, China. METHODS: The incidence and outcome of IHCAs over a 12-month period were evaluated in this prospective study. Between January 1 and December 31, 2014, 12 Beijing hospitals prospectively participated in this study for calculation of the incidence of IHCA. Data were collected according to the Utstein style for all cases of attempted resuscitation for IHCA that occurred in the participating hospitals. Surviving patients were followed for 1 month. RESULTS: The total number of admissions across the 12 hospitals during this 1-year period was 582,242; the IHCA incidence was 17.5 per 1000 admissions. Of the 10,198 IHCAs recorded, cardiopulmonary resuscitation (CPR) was initiated in 26.6%. Among CPR recipients, 1292 (47.6%) had a presumed cardiac aetiology and 1255 occurred in the Emergency Department. With regards to initial rhythm, 1340 had asystole and 423 had shockable rhythms. Of those receiving CPR, 1451 (53.5%) patients received it in less than 1min. Restoration of spontaneous circulation was achieved in 962 (35.5%) patients; 247 (9.1%) patients were discharged alive and 174 (6.4%) patients had good neurological outcomes. At 1 month after discharge, 236 patients remained alive. On multivariate regression analysis, factors associated with survival included female sex, age <60 years, and ventricular fibrillation/ventricular tachycardia as the initial rhythm. CONCLUSION: The incidence of IHCA in Beijing hospitals is high and the survival is poor compared to other industrialized countries.

Preparation and characterization of a novel injectable strontium-containing calcium phosphate cement with collagen.

PURPOSE: To develop a novel injectable strontium-containing calcium phosphate cement with collagen. METHODS: A novel calcium phosphate bone cement (CPC) was prepared with the addition of strontium element, collagenl, and modified starch; the injectability, solidification time, microstructure, phase composition, compressive strength, anti-collapsibility and histological properties of material were evaluated. RESULTS: The results showed that the material could be injected with an excellent performance; the modified starch significantly improved the anti-washout property of cement; with the liquid to solid ratio of 0.3, the largest compressive strength of cement was obtained (48.0 MPa ± 2.3 MPa); histological examination of repair tissue showed that the bone was repaired after 16 weeks; the degradation of cement was consistent with the new bone growth. CONCLUSION: A novel injectable collagen-strontium-containing CPC with excellent compressive strength and suitable setting time was prepared, with addition of modified starch. The CPC showed a good anti-washout property and the degradation time of the cement met with the new bone growing. This material is supposed to be used in orthopedic and maxillofacial surgery for bone defects.

Classification of gluteal muscle contracture in children and outcome of different treatments.

BACKGROUND: Gluteal muscle contracture (GMC) is a clinical syndrome due to multiple etiologies in which hip movements may be severely limited. The aim of this study was to propose a detailed classification of GMC and evaluate the statistical association between outcomes of different management and patient conditions. METHODS: One hundred fifty-eight patients, who were treated between January 1995 and December 2004, were reviewed at a mean duration of follow-up of 4.8 years. Statistical analyses were performed using X2 and Fisher's exact tests. RESULTS: Non-operative management (NOM), as a primary treatment, was effective in 19 of 49 patients (38.8%), while operative management was effective in all 129 patients, with an excellence rating of 83.7% (108/129). The outcome of NOM in level I patients was significantly higher than in level II and III patients (P < 0.05). The results of NOM and operative management in the child group were better than the adolescent group (P < 0.05). Complications in level III were more than in level II. CONCLUSION: NOM was more effective in level I patients than in level II and III patients. Operative management was effective in patients at all levels, with no statistical differences between levels or types. We recommend NOM as primary treatment for level I patients and operative management for level II and III patients. Either NOM or operative management should be carried out as early as possible.

[Isolation, culture and purification of olfactory ensheathing cells from human fetal olfactory mucosa].

OBJECTIVE: To explore the method for obtaining olfactory ensheathing cells from human fetal olfactory mucosa by cell culture for selective adhesion in the presence of neurotrophin-3 (NT3) and low-concentration serum. METHODS: The olfactory ensheathing cells were cultured alternatively in DMEM/F12 culture medium containing 10% fetal bovine serum (FBS) and the medium containing NT3 and 2.5% FBS every 72 h. The cells were observed for morphological changes and identified using immunocytochemistry with P75NTR and GFAP, and the cell purity was estimated. RESULTS: The olfactory ensheathing cells from human fetal olfactory mucosa were positive for P75(NTR) and GFAP, and in in vitro culture, the cells exhibited dipolar or tripolar appearance with long thin neurites. On the 9th day of cell culture, the purity of the olfactory ensheathing cells reached about 83%. CONCLUSION: The olfactory ensheathing cells can be obtained by in vitro culture for selective adhesion in the presence of NT3 and low-concentration serum.

[Culture and purification of olfactory ensheathing cells from human fetal using different attachment rates combined with the technique of using NT3 intermittently].

AIM: To explore a simple and pragmatic method to obtain sufficient olfactory ensheathing cells from human fetal by using different attachment rates in harvested cells with the combinating of the technique of using NT3 intermittently. METHODS: DMEM/F12 culture solution including 100 mL/L of fetal bovine serum or including NT3 was used to culture olfactory ensheathing cells intermittently every 48 h. The conditions and growth degree of OECs were observed, and P75 immunocytochemistry was used to estimate the purity of the cells. RESULTS: Human fetal OECs were positive after P75 immunocytochemistry. They appeared to be dipolar or tripolar cells and their processes formed a network in vitro. The purity of OECs in good conditions reached about 95% on 9 d and 83% on 12 d. CONCLUSION: The method of using different attachment rates combined with the technique of using NT3 intermittently can culture and purify OECs simply and effectively.

[Characteristics of aerobic granular sludge membrane bioreactor for wastewater treatment].

Characteristics of aerobic granular sludge membrane bioreactor (MBR) and the membrane fouling were studied with synthetic wastewater. Experimental results showed that COD removal rate could be reached over 96% under the conditions of HRT = 6h, DO 4 - 6 mg x L(-1) and the volumetric load of COD = 7.24 kg x (m3 x d)(-1). When the volumetric load of NH3-N was 0.17 kg x (m3 x d)(-1), the removal rate of NH3-N was about 60%. The variations of the COD/N ratio could not affect the removal of COD and NH3-N. During the stable operation process, MLSS of the reactor was as high as 14 - 16 mg x L(-1), which could conduce simultaneous nitrification-denitrification, as the anoxic and anaerobic microorganisms might be existed in the core of granular sludge. In addition, the membrane flux of MBR of two different configurations of sludge, granular sludge and floccular sludge, was compared. The flux reduction of granular sludge MBR was much lower than that of floccular sludge MBR. Moreover, the membrane permeability of the granular sludge MBR could be regained simply by backwashing with aeration or washing the membrane with water.