Nanosilicate-functionalized nanofibrous membrane facilitated periodontal regeneration potential by harnessing periodontal ligament cell-mediated osteogenesis and immunomodulation.

Although various new biomaterials have enriched the methods for periodontal regeneration, their efficacy is still controversial, and the regeneration of damaged support tissue in the periodontium remains challenging. Laponite (LAP) nanosilicate is a layered two-dimensional nanoscale, ultrathin nanomaterial with a unique structure and brilliant biocompatibility and bioactivity. This study aimed to investigate the effects of nanosilicate-incorporated PCL (PCL/LAP) nanofibrous membranes on periodontal ligament cells (PDLCs) in vitro and periodontal regeneration in vivo. A PCL/LAP nanofibrous membrane was fabricated by an electrospinning method. The characterization of PCL/LAP nanofibrous membrane were determined by scanning electron microscopy (SEM), energy dispersive spectrum of X-ray (EDS), inductively coupled plasma mass spectrometry (ICP-MS) and tensile test. The proliferation and osteogenic differentiation of PDLCs on the PCL/LAP nanofibrous membrane were evaluated. A PDLCs and macrophage coculture system was used to explore the immunomodulatory effects of the PCL/LAP nanofibrous membrane. PCL/LAP nanofibrous membrane was implanted into rat calvarial and periodontal defects, and the regenerative potential was evaluated by microcomputed topography (micro-CT) and histological analysis. The PCL/LAP nanofibrous membrane showed good biocompatibility and bioactivity. It enhanced the proliferation and osteogenic differentiation of PDLCs. The PCL/LAP nanofibrous membrane also stimulated anti-inflammatory and pro-remodeling N2 neutrophil formation, regulated inflammatory responses and induced M2 macrophage polarization by orchestrating the immunomodulatory effects of PDLCs. The PCL/LAP nanofibrous membrane promoted rat calvarial defect repair and periodontal regeneration in vivo. LAP nanosilicate-incorporated PCL membrane is capable of mediating osteogenesis and immunomodulation of PDLCs in vitro and accelerating periodontal regeneration in vivo. It could be a promising biomaterial for periodontal regeneration therapy.

Site-specific periosteal cells with distinct osteogenic and angiogenic characteristics.

OBJECTIVES: This study aimed to investigate the site-specific characteristics of rat mandible periosteal cells (MPCs) and tibia periosteal cells (TPCs) to assess the potential application of periosteal cells (PCs) in bone tissue engineering (BTE). MATERIALS AND METHODS: MPCs and TPCs were isolated and characterized. The potential of proliferation, migration, osteogenesis and adipogenesis of MPCs and TPCs were evaluated by CCK-8, scratch assay, Transwell assay, alkaline phosphatase staining and activity, Alizarin Red S staining, RT‒qPCR, and Western blot (WB) assays, respectively. Then, these cells were cocultured with human umbilical vein endothelial cells (HUVECs) to investigate their angiogenic capacity, which was assessed by scratch assay, Transwell assay, Matrigel tube formation assay, RT‒qPCR, and WB assays. RESULTS: MPCs exhibited higher osteogenic potential, higher alkaline phosphatase activity, and more mineralized nodule formation, while TPCs showed a greater capability for proliferation, migration, and adipogenesis. MPCs showed higher expression of angiogenic factors, and the conditioned medium of MPCs accelerated the migration of HUVECs, while MPC- conditioned medium induced the formation of more tubular structure in HUVECs in vitro. These data suggest that compared to TPCs, MPCs exert more consequential proangiogenic effects on HUVECs. CONCLUSIONS: PCs possess skeletal site-specific differences in biological characteristics. MPCs exhibit more eminent osteogenic and angiogenic potentials, which highlights the potential application of MPCs for BTE. CLINICAL RELEVANCE: Autologous bone grafting as the main modality for maxillofacial bone defect repair has many limitations. Constituting an important cell type in bone repair and regeneration, MPCs show greater potential for application in BTE, which provides a promising treatment option for maxillofacial bone defect repair.

Enhanced Arylamine N-Oxygenase Activity of Polymer-Enzyme Assemblies by Facilitating Electron-Transferring Efficiency.

A novel N-oxygenase-coated core-shell nanoparticle was generated through the coassembly of poly(4-vinylpyridine) (P4VP) and arylamine N-oxygenase CmlI. The resulting enzyme-hybridized particles, P4VP-CmlI, showed excellent catalytic activities on the oxidation of two arylamine substrates, i.e., p-aminophenol ( pAP) and p-aminobenzoic acid ( pABA), using a surrogate redox system or a peroxide shunt as co-oxidants. In comparison with the free enzyme, P4VP-CmlI particles exhibited a significantly enhanced catalytic efficiency when using pyridine nucleotide (NADH) and proper redox mediators. Products at different oxygenation stages were observed. On the contrary, the activity of the enzyme-containing nanoparticles was very similar to the free enzyme when using the peroxide shunt. The enhanced catalytic efficiency of the P4VP-CmlI assemblies is attributed to a more efficient electron delivery.

Nanosilicate-Functionalized Polycaprolactone Orchestrates Osteogenesis and Osteoblast-Induced Multicellular Interactions for Potential Endogenous Vascularized Bone Regeneration.

Massive oral and maxillofacial bone defect regeneration remains a major clinical challenge due to the absence of functionalized bone grafts with ideal mechanical and proregeneration properties. In the present study, Laponite (LAP), a synthetic nanosilicate, is incorporated into polycaprolactone (PCL) to develop a biomaterial for bone regeneration. It is explored whether LAP-embedded PCL would accelerate bone regeneration by orchestrating osteoblasts to directly and indirectly induce bone regeneration processes. The results confirmed the presence of LAP in PCL, and LAP is distributed in the exfoliated structure without aggregates. Incorporation of LAP in PCL slightly improved the compressive properties. LAP-embedded PCL is biocompatible and exerts pronounced enhancements in cell viability, osteogenic differentiation, and extracellular matrix formation of osteoblasts. Furthermore, osteoblasts cultured on LAP-embedded PCL facilitate angiogenesis of vessel endothelial cells and alleviate osteoclastogenesis of osteoclasts in a paracrine manner. The addition of LAP to the PCL endows favorable bone formation in vivo. Based upon these results, LAP-embedded PCL shows great potential as an ideal bone graft that exerts both space-maintaining and vascularized bone regeneration synergistic effects and can be envisioned for oral and maxillofacial bone defect regeneration.

Antibody fragment-conjugated gemcitabine and paclitaxel-based liposome for effective therapeutic efficacy in pancreatic cancer.

In this study, we have developed an antibody fragment (AF)-conjugated gemcitabine (GEM) and paclitaxel (PTX)-loaded liposome (AF-GPL) to enhance the therapeutic efficacy in pancreatic cancer treatment. The maleimide-thiol chemistry was utilized to conjugate AF on the liposome surface. The dual-drug loaded liposome was nanosized and exhibited a controlled release of both the drugs. Importantly, two drugs have different release pattern over a period of time. The AF-conjugated liposome showed enhanced cellular uptake in pancreatic cancer cells compared to that of non-targeted liposome. Two-fold higher internalization of particles might increase the intracellular concentration of anticancer drugs that might further increase the therapeutic efficacy in pancreatic cancer cells. AF-GPL showed significantly higher cytotoxic effect in pancreatic cancer cell compared to that of non-targeted GPL. The IC50 value of GEM, PTX, GPL and AF-GPL were 5.9 µg/ml, 4.2 µg/ml, 1.92 µg/ml, and 0.45 µg/ml, respectively. Consistently, AF-GPL (4.12) showed significantly higher ratio of Bax/Bcl-2 compared to that of non-targeted GPL (2.8). Importantly, AF-GPL induced a significant apoptosis of cancer cells with predominant amount of cells in late apoptosis cells. Overall, AF-conjugated nanosystem could potentially improve the therapeutic efficacy in pancreatic cancers.

[Investigation of dental manpower in non-public dental institutions in Liaoning province].

PURPOSE: To investigate the non-public oral medical institutions in Liaoning province in 2011, and to analyze the status of dental manpower in non-public dental institutions in Liaoning province. METHODS: A mass survey on dental manpower was made in non-public dental institutions in Liaoning province in 2011 by means of questionnaire investigation, which included the institution type, dental devices, and the number, structure, composition, distribution of dental manpower in non-public dental institutions in Liaoning province. Data was entered with EpiData 3.0 and analyzed with SPSS 13.0 software package. RESULTS: There were 1649 non-public dental institutions with 3132 dentists, 1265 nurses, 540 technicians and 3490 dental chairs in Liaoning province. 85.69% of the dental manpower were young and middle-aged. 33.17% of the dentists had primary professional titles, 42.53% of them had college degree and 87.96% of the dentists was general dentistry. In the dental auxiliaries, the primary professional title accounted for the majority. 95.97% of the nurses majored in general dentistry and 60.40% of the nurses' educational background were below junior college degree. 72.59% of the technicians majored in prosthetic dentistry and 67.78% of their educational background were below junior college degree. The ratio of the dentists to nurses to technicians was 6:2:1. The ratio of the nurses to dental chairs was 1:2.76. CONCLUSIONS: The distribution and composition of dental manpower are not reasonable in non-public dental institutions in Liaoning province. We should strengthen effective utilization of oral health resources and the oral health service ability of non -public dental institutions in Liaoning province. Supported by Key Science and Technology Projects of Liaoning Province (2012225015).

[Investigation of the medical institutions of stomatology and dental manpower distribution in Liaoning province].

PURPOSE: The aim of this investigation was to determine and analyze the distribution of the medical institutions of stomatology and dental manpower in Liaoning province. METHODS: The data of institutions and manpower was collected by mass examination using tables filled by every institution and personally. Epidata 3.02 database was used to input the data and statistical analysis was performed using the SPSS12.0 software package. RESULTS: The results showed that there were 2155 dental institutions and 5617 dentists in Liaoning province. Among all the institutes, 71.0% was private clinics. About 80.5% of institutions and 87.8% of dentists were in the urban area, which was significantly higher than the percent of dentists working in the rural area. The ratio between dentists and the general population was about 13.02/10 million. There were fewer dental auxiliary in dental institutions, the ratio between dentists, nurses and dental technician was 6:2:1. The title and degree of the dentists in the rural area were lower than those in urban area, but the dentists in the rural area provided service for a large population. CONCLUSION: The results suggest that the distribution of oral health resource in Liaoning province should be rationally readjusted, and continuing education and training should be strengthened in order to improve the efficiency of oral health service and social health justice. Supported by Key Medical Professional Construction Project of Liaoning Province (Grant No.200809).