Assessment of nano-hydroxyapatite and poly (lactide-co-glycolide) nanocomposite microspheres fabricated by novel airflow shearing technique for in vivo bone repair.

A novel airflow shearing method was introduced to prepare microspheres efficiently with precisely control of microsphere size and homogeneity. The effects of technical parameters in the formation of the microspheres, such as solution concentration, nozzle size and airflow strength, were investigated. By optimizing the technical parameters (8% PLGA concentration, 27-32 G nozzle size, 6-8 l/min airflow strength), nano-hydroxyapatite and poly(lactide-co-glycolide) nanocomposite (nHA/PLGA) microspheres with a diameter around 250 µm and up to 40 wt% nHA content was prepared successfully. Especially, the microspheres possessed revealed great homogeneity and unique "acorn" appearance with two sides: A hard smooth side as well as a crumpled rough side, generated in the preparation process. Furthermore, the nHA/PLGA microspheres' potential application in bone tissue engineering was studied. In vitro, enhanced proliferation and osteogenic differentiation of the MC3T3-E1 cells was observed on as-prepared nHA/PLGA microspheres with high nHA content. In vivo, the BV/TV value of the microspheres with 20 wt% nHA was up to 75% and similar to the clinical products' performance. Moreover, beside high nHA content, the rough porous surface leads to bone ingrowth, which plays an important role in accelerating bone repair. Therefore, airflow shearing method could be an effective approach to fabricate biocompatible microsphere, and the as-prepared microspheres showed unique surface state and bone repair ability and making them as potential candidates for bone tissue engineering and bone implantation clinical applications.

High-affinity, neutralizing antibodies to SARS-CoV-2 can be made in the absence of T follicular helper cells

T follicular helper (Tfh) cells are the conventional drivers of protective, germinal center (GC)-based antiviral antibody responses. However, loss of Tfh cells and GCs has been observed in patients with severe COVID-19. As T cell-B cell interactions and immunoglobulin class switching still occur in these patients, non-canonical pathways of antibody production may be operative during SARS-CoV-2 infection. We found that both Tfh-dependent and -independent antibodies were induced against SARS-CoV-2 as well as influenza A virus. Tfh-independent responses were mediated by a population we call lymph node (LN)-Th1 cells, which remain in the LN and interact with B cells outside of GCs to promote high-affinity but broad-spectrum antibodies. Strikingly, antibodies generated in the presence and absence of Tfh cells displayed similar neutralization potency against homologous SARS-CoV-2 as well as the B.1.351 variant of concern. These data support a new paradigm for the induction of B cell responses during viral infection that enables effective, neutralizing antibody production to complement traditional GCs and even compensate for GCs damaged by viral inflammation. One-Sentence SummaryComplementary pathways of antibody production mediate neutralizing responses to SARS-CoV-2.

Growth Inhibition Effect and Validation of Stable Expressed Reference Genes for Near-Infrared Photothermal Therapy Mediated by Gold Nanoflower Particles on Human Tongue Carcinoma Tca-8113 Cells.

Compared with surgery, radiotherapy, chemotherapy and other conventional cancer treatments, near-infrared (NIR) photothermal therapy mediated by gold nanoparticles had advantages of non-invasive, safe, non-drug resistance and small side effects. Especially for tongue cancer and other head and neck tumors, NIR gold nanoparticle-mediated photothermal therapy is more conducive to preserve the anatomic and functional integrity of stomatognathic system, improving the life quality of patients. However, the toxic organic phase substances are commonly used in conventional gold nanoparticles preparation process in order to increase the stability of the material which limited its application in the biomedical field. In this study, a new type of gold nanoflower (GNF) particles were synthesized by seeding approach in aqueous phase, with better biocompatibility and free of organic substances. Then, the photo-thermal conversion curve under the irradiation of NIR laser ray were investigated. The absorption peak of prepared GNF particles was 719 nm and they had high efficient photothermal conversion in near-infrared region. Furthermore, we investigated the inhibition effect of NIR photothermal therapy with different laser power mediated by the GNF particles on human tongue carcinoma cells by detecting the relative growth rate, cell cycle, and apoptosis and necrosis. The results showed that NIR photothermal therapy mediated by prepared GNF particles could inhibit proliferation of tongue carcinoma Tca-8113 cells obviously, and the relative growth rate of Tca-8113 cells decreased along with the increasing of GNF concentration and laser power. At last, we validated the expression stabilities of 12 commonly used reference genes (18S, ACTB, ALAS1, GAPDH, TBP, HPRT1, RPL29, HMBS, PPIA, PUM1, GUSB, and B2M) after the above treatment through real-time quantitative polymerase chain reaction (RT-qPCR). Three commonly used software, geNorm, NormFinder, and BestKeeper are used to compare stability between reference genes. The final ranking of the candidate reference genes expression stability was TBP > PPIA > RPL29 > B2M > 18S rRNA > GAPDH > GUSB > ACTB > HPRT1 > ALAS1 > HMBS > PUM1. The combination of TBP + PPIA is best for normalizing the relative quantitation. The results suggested that GNF particles had high photothermal conversion in NIR region and was ideal mediated material for tumor NIR photothermal therapy. NIR photothermal therapy mediated by GNFs could inhibit the growth rate of tongue carcinoma Tca-8113 cells obviously. The recommend reference genes can be used for improving the accuracy of gene expression studies in the molecular mechanism of near-infrared (NIR) photothermal therapy mediated by the gold nanoflower (GNF) particles.

Expressions of heat shock protein 70,P27 and Bcl-2 protein in mucoepidermoid carcinoma of salivary glands and clinical significances / 吉林大学学报(医学版)

Objective To study the expressions of Hsp70,P27,Bcl-2 in mucoepidermoid carcinoma of salivary glands and clinical significances.Methods Forty cases of mucoepidermoid carcinoma of salivary glands were chosen and the expressions of Hsp70,P27,Bcl-2 were detected by the method of immunohistochemistry,10 cases of polymorphic adenoma were chosen as control group.Results Both Hsp70 and P27 were stained with aliomycin in nucleus and cytoplasm,the positive rates of them were 75% and 27.5%,respectively,there were significant differences compared with control group(P0.05).The expressions of Hsp70 and P27 had significant differences in different clinical stages,different histological grades and lymph node metastasis(P0.05).Conclusion The expressions of Hsp70 and P27 can be used to estimate prognosis of patients with mucoepidermoid carcinoma.Hsp70 and Bcl-2 can inhibit apoptosis by different ways.

A quasi-experimental research on hospitalization process recombination for common disease entities in general surgery / 中华医院管理杂志

Objective To shorten the average length of stay for single disease entities and enhance the hospitals competitiveness through hospitalization process recombination while guaranteeing the quality of its medical service. Method The method of "systematic reintegration" from the theory of operation process recombination was adopted to recombine the hospitalization process for common disease entities in general surgery. Result After the recombination, the number of discharged patients with disease entities covered by the year 2000 research increased by 14.78%, the average length of stay was shortened by 3.83 days, a reduction of 21.58%, the average hospitalization fees incurred on the patients were reduced by 108 yuan, a reduction of 1.18%, and the business income increased by 13.43%, as compared with 1999, when recombination was not yet initiated. Conclusion Hospitalization process recombination can improve the quality and efficiency of a hospitals medical service and increase its business income while its medical service resources remain unchanged.