The surface modification using cold plasma technique was introduced to hydroxyapatite(HA). The methods adopted in the study included the formation of bone-like apatite in simulated body fluid and the use of SEM, XPS and XRD. The results showed that the formation of bone-like apatite on HA modified by cold plasma was easier than that without modification. The active mechanism involves the impact of the particles with high energy and high activity against HA, which roughens and etches the surface of HA, heads to the distortion of HA crystal, and thus increases the dissolvability of HA and the local concentration of the Ca and P ions. This approach is helpful to the formation of bone-like appetite. The data demonstrate that the surface modification using cold plasma technique can increase the activity of HA.
Apatites ; chemistry ; Biocompatible Materials ; chemistry ; Cold Temperature ; Durapatite ; chemistry ; Humans ; Plasma ; chemistry ; Surface Properties

BACKGROUNDProtein kinase C(PKC) is a potentially important target for can-cer therapeutics due to its potential role in carcinogenesis.Abnormal expression and increasing activity of PKC-α are present in non-small cell lung cancer(NSCLC).PKC inhibitor can show anti-tumor effects through inducing tumor cell apoptosis,enhancing cytotoxic effects and down-regulating expressions of multidrug resistance gene.By observing the effects of PKC inhibitor chelerythrine chloride(CH) on drug-sensitivity to cisplatin of four NSCLC cell lines its mechanism of effect initially is explored.

METHODSNSCLC cell lines(H1299,H460,A549 and cisplatin-resistant A549) were dealed with PKC inhibitor CH respectively.The expressions of PKC-α mRNA and protein in NSCLC cell lines were examined by reverse transcription polymerase chain reaction(RT-PCR) and Western blot.The apoptosis rates of NSCLC cells lines were detected by flow cytometry.The drug-sensitivity to cisplatin of NSCLC cells lines was measured by methabenzthiazuron(MTT) assay.

RESULTSThe expression levels of PKC-α mRNA and protein in cisplatin-resistant A549 cell lines were significantly higher than H1299,H460 and parent A549 cell lines(P < 0.05).The expression levels of PKC-α mRNA and protein in four NSCLC cell lines decreased at different extent.The apoptosis rates of cisplatin-resistant A549 cell lines increased obviously after treating with CH for 4 and 24 hours,but it was not seen in H1299,H460 and parent A549 cell lines.The IC50 value of cisplatin of NSCLC cell lines decreased at different degree after treating with CH and it was more obvious in cisplatin-resistant A549 cell lines(P < 0.05).

CONCLUSIONSHigh expressions of PKC-α mRNA and protein exist in all four NSCLC cell lines.PKC inhibitor CH can enhance the drug-sensitivity of NSCLC cell lines to cisplatin by inhibiting their expression of PKC-α mRNA and protein.When compared with parent A549 cell lines,cisplatin-resistant A549 cell line's drug-sensitivity to cisplatin is increasing more efficiently by PKC inhibitor CH through inhibition of PKC-α protein's expression and elevation of tumor cell apoptosis rates.

With the development of computer and digital technology, the application of computer-aided technology has become a new trend in the field of oral implant. Computer-guided oral implant surgery has the advantages of being safer and more accurate than traditional implant surgery, and it can truly realize the concept of restoration-oriented implant. However, computer-guided oral implant surgery has various steps which cause deviations accumulation, so that some clinicians remain sceptical about the accuracy of the technology. Currently, due to the lack of a quantitative system for evaluating the accuracy of computer-guided oral implantation, the implant deviation in each step is still inconclusively in the stage of research and debate. The purpose of this paper is to summarize the advantages and disadvantages, research progress, accuracy and influencing factors of computer-guided oral implantation, aiming to provide a reference for improving implant accuracy and guiding clinical design and surgery.
Computer-Aided Design ; Computers ; Cone-Beam Computed Tomography ; Dental Implants ; Imaging, Three-Dimensional ; Patient Care Planning ; Surgery, Computer-Assisted