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Electrical Discharge Machine (EDM) parameters have a significant influence on machining characteristic like material removal rate (MMR) and tool wear rate (TWR). Inconel 718, which is widely used in the Medical, Marine, Architectural and food processing industries, is used as a work material. The tool electrode materials used are brass and copper. Experiments are conducted using face centered central composite design to determine the effects of process parameters like current rate, pulse on time, pulse off time and concentration of titanium carbide nano particle in dielectric fiuid. Based upon the experimental outcomes, the effect of brass and copper electrodes during electric discharge machining of Inconel 718 using nano particles mixed dielectric fiuid was investigated.
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Vaccination has been proved to be the most effective strategy to prevent the Corona Virus Disease 2019 (COVID-19). The mRNA vaccine based on nano drug delivery system (NDDS) - lipid nanoparticles (LNP) has been widely used because of its high effectiveness and safety. Although there have been reports of severe allergic reactions caused by mRNA-LNP vaccines, the mechanism and components of anaphylaxis have not been completely clarified yet. This review focuses on two mRNA-LNP vaccines, BNT162b2 and mRNA-1273. After summarizing the structural characteristics, potential allergens, possible allergic reaction mechanism, and pharmacokinetics of mRNA and LNP in vivo, this article then reviews the evaluation methods for patients with allergic history, as well as the regulations of different countries and regions on people who should not be vaccinated, in order to promote more safe injection of vaccines. LNP has become a recognized highly customizable nucleic acid delivery vector, which not only shows its value in mRNA vaccines, but also has great potential in treating rare diseases, cancers and other broad fields in the future. At the moment when mRNA-LNP vaccines open a new era of nano medicine, it is expected to provide some inspiration for safety research in the process of research, development and evaluation of more nano delivery drugs, and promote more nano drugs successfully to market.
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ABSTRACT Purpose: To investigate the antiproliferative effect of carboplatin-loaded surface-modified poly(lactide-co-glycolide) on retinoblastoma cells. Methods: Carboplatin-loaded poly(lactide-co-glycolide) with or without sodium alginate surface modification was prepared using sodium alginate-poly(lactide-co-glycolide) and poly(lactide-co-glycolide). The zeta potential and carboplatin release behavior were investigated. The cellular uptake of the released drug was observed in the retinoblastoma cell line Y79. The inhibitory effect of carboplatin-loaded nanoparticles against the Y79 cell line was evaluated using methyl thiazolyl tetrazolium assay and western blot. Native carboplatin and void nanoparticles without carboplatin loading were used as controls. Results: The zeta potential was -(26.1 ± 3.1) mV for carboplatin-loaded poly(lactide-co-glycolide) and-(43.1 ± 8.1) mV for carboplatin-loaded sodium alginate-poly(lactide-co-glycolide). The burst release percentages of carboplatin-loaded poly(lactide-co-glycolide) and sodium alginate-poly(lactide-co-glycolide) were (40.0% ± 8.2%) and (18.9% ± 4.3%) at 24 hours, respectively. A significant difference was identified regarding drug release between carboplatin-loaded sodium alginate-poly(lactide-co-glycolide) and carboplatin-loaded poly(lactide-co-glycolide). Fluorescence detection revealed that intense uptake of carboplatin into the cytoplasm of the Y79 cell line that was exposed to carboplatin-loaded sodium alginate-poly(lactide-co-glycolide). Carboplatin-loaded poly(lactide-co-glycolide) or sodium alginate-poly(lactide-co-glycolide) exposure inhibited proliferating cell nuclear antigen expression in Y79 cells on day 3. Extension of exposure to day 5 revealed that the sodium alginate-poly(lactide-co-glycolide) surface modification was superior to that of poly(lactide-co-glycolide) in terms of proliferating cell nuclear antigen inhibition. The cell viability test using methyl thiazolyl tetrazolium revealed a similar inhibitory effect. Furthermore, the carboplatin-loaded nanoparticles of lower concentration inhibited cell viability more strongly than native carboplatin of higher concentration in methyl thiazolyl tetrazolium assay. Conclusions: Carboplatin-loaded sodium alginate-poly(lactide-co-glycolide) inhibited retinoblastoma cell proliferation with superior effect as compared with poly(lactide-co-glycolide) and native carboplatin. Sodium alginate surface modification offers a potential strategy for the sustained carboplatin release system.
RESUMO Objetivo: Investigar o efeito antiproliferativo de poli (lactídeo-coglicolídeo) com superfície modificada carregada com carboplatina contra células de retinoblastoma. Métodos: Preparou-se poli (lactídeo-co-glicolídeo) carregado com carboplatina com ou sem alginato de sódio para modifição da superfície, poli com alginato de sódio (lactídeo-co-glicolídeo) e poli (lactídeo-co-glicolídeo). O potencial zeta e o comportamento de liberação de carboplatina foram investigados. A captação celular do fármaco liberado foi observada na linha celular de retinoblastoma Y79. O efeito inibitório das nanopartículas carregadas com carboplatina contra a linha celular Y79 foi avaliado através do ensaio de metiltiazol tetrazólio e Western-blot. Carboplatina nativa e nanopartículas vazias sem carga de carboplatina serviram como controles. Resultados: O potencial zeta de poli carregado com carboplatina (lactídeo-co-glicolídeo) foi - (26,1 ± 3,1) mV versus - (43,1 ± 8,1) mV em poli com alginato de sódio carregado com carboplatina (lactídeo-co-glicolídeo). A percentagem de libertação de explosão de poli carregado com carboplatina (lactídeo-co-glicolídeo) e poli com alginato de sódio (lactídeo-co-glicolídeo) foram (40,0 ± 8,2)% e (18,9 ± 4,3)% às 24 horas, respectivamente. Uma diferença significativa foi identificada em relação à liberação de fármaco entre poli com alginato de sódio carregado com carboplatina (lactídeo-co-glicolídeo) e poli carregado com carboplatina (lactídeo-co-glicolídeo). A detecção de fluorescência revelou que a carboplatina foi assimilada intensamente no citoplasma da linha celular Y79 que foi exposta ao poli com alginato de sódio carregado com carboplatina (lactídeo-co-glicolídeo). A exposição de poli carregada com carboplatina (lactídeo-co-glicolídeo) ou poli com alginato de sódio (lactídeo-co-glicolídeo) inibiu a expressão de antígeno nuclear de proliferação celular em células Y79 no 3º dia. A extensão da exposição no 5º dia revelou que poli com alginato de sódio (lactídeo-co-glicolídeo) para modificação da superfície foi superior a poli (lactídeo-co-glicolídeo) em termos de inibição do antígeno nuclear de proliferação celular. O teste de viabilidade celular via metiltiazol tetrazólio mostrou um efeito inibitório semelhante. Além disso, as nanopartículas carregadas com carboplatina de concentração mais baixa inibiram a viabilidade celular mais fortemente em comparação com a carboplatina nativa de concentração mais alta no ensaio de metiltiazol tetrazólio. Conclusões: Poli com alginato de sódio carregado com carboplatina (lactídeo-co-glicolídeo) inibiu a proliferação de células de retinoblastoma com efeito superior em contraste com poli (lactídeo-co-glicolídeo) e carboplatina nativa. O alginato de sódio para modificação da superfície oferece uma estratégia potencial para o sistema de liberação de carboplatina sustentada.
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Objective To investigate the inhibitory effects of chitosan nano-particles loaded tetrandrine (Tet) on proliferation of cultured pterygium fibroblasts.Methods The deoxycholic acid-modified chitosan (DAMC) derivative was synthesized through amidation reaction,and their properties were investigated.The viability of human pterygium fibroblasts (HPF) was evaluated by cell counting kit-8 (CCK-8) assay after cells were interacted with Tet/DAMC nano-particles on day 1,3 and 5.Results The synthesized chitosan derivative and Tet formed drug-loaded nano-particles,and the agent-loading capacity was approximately 76％,and the sizes of agent-loaded nano-particles were 50-500 nm,with Zeta potential values being positive.The result of in vitro drug release experiment indicated that the nano-particles constantly released Tet in a controlled manner within 48 h.The viability of HPF in Tet group was (60.70 ± 2.30) ％,(50.22 ± 2.35) ％,(21.99 ± 2.07) ％ on day 1,3,5,respectively,but the corresponding data in Tet/DAMC group was (79.77 ±2.09)％,(63.24 ±2.83)％,(40.28 ± 1.19)％,respectively.The CCK-8 assay demonstrated that the Tet/DAMC nano-particles could inhibit HPF proliferation,and presented lower toxicity than Tet alone.Conclusion Chitosan nano-particles loaded tetrandrine exhibits a sustained agent-release behavior,which has obvious inhibitory effects on the proliferation of human pterygium fibroblasts,but its cytotoxicity is significantly lower than the original drug's,thereby possessing a great promise for improving the outcome of Tet for the prevention of pterygium recurrence.
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OBJECTIVE: To prepare valsartan nano-suspensions and solidify the suspensions.
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Objective To identify the effective results of ultrasound in degradation of polymeric nanoparticles released DNA .Polymeric nanoparticles was made by dehydration of polyacetylglutamicacid (PLGA, polylactic-co-glycolic acid)solution. Method Green Fluorescent Protein (GFP) was enclosed by PLGA. Different kinds of ultrasound mode and different duct cycle and power ones were used to radiate PLGA solution for 90 s, 9 min, 20 min separately after the solution prepared for 2 hrs,then putted the solution on centrifugal machine at 13000 r/m. Using Choloroform to get rid of fat-soluble impurity,then applied nanodrop to survey the releasing rate of DNA. Finally the effect of cell expression were observed by fluorescent microscope. Results The amount of DNA released from PLGA in groups which were exposed to ultrasound were significantly different from the groups which were not exposed to ultrosound. The releasing amount of former groups had upper limitation. The releasing rate was increased with the increment of the irradiation time,frequency of ultrasound;The effect of the DNA releasing and PLGA degradation by continuous-wave irradiation was stronger than pulsed-wave ultrasound. Conclusion Ultrasound can promote the degradation of PLGA, and do help in DNA releasing and expression in vitro.
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Objective To investigate the clinical application and curative effect of Carbon Nano-particles in curative resection of mid-low rectal cancer .Methods 26 patients with mid-low rectal cancer were divided equally into carbon nano-particle group and routine group .The labeling group were injected with carbon nano-particles 20~24 hours before operation and treated with TME laparoscopic radical resection .The data of lymph nodes detected in the two groups were compared .Results (1)Total number of lymph nodes detected in the labeling group was higher than that of the routine group (287 vs .124 ,P0 .05) .Con-clusion Adoption of carbon nano-particle in curative resection of rectal cancer can increase the number of lymph nodes detected ,re-veal more accurately the metastasis situation of lymph nodes ,facilitate the resection of lymph nodes and rectal cancer during the op-eration ,and provide guidance for postoperative clinical staging and treatment .
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In our present study the conventional (physical and chemical) method of nano particles synthesis was replaced with biological synthesis of silver nanoparticles by using the leaf extract of Wrightia tinctoria. New drug delivery system has been enhanced with noval techniques like nano particle synthesis and its role in drug delivery system, by exploiting the nanotechnology in particle synthesis. The aqueous extract of Wrightia tinctoria leaves was prepared and mixed with 1mM AgNO3 solution. After 48 hours the reduction of silver nitrate to silver nanoparticles (AgNPs) was confirmed by UV-visible spectrophotometer. The size of Silver nanoparticles were characterized by XRD and FTIR and the size were of 19 – 68nm. The biosynthesis of AgNPs using Wrightia tinctoria leaf extract is very simple and economic. This green chemistry approach is amenable to large scale commercial production. The use of environmentally benign and renewable plant material offers enormous benefits of eco-friendliness.
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[Objective]To study the degradation of nano-nacre powder and the biocompatibility of the composite artificial bone made from this nano-scale powder in vivo.[Method]The nano-nacre powder made through mechanical grinding and the artificial bones made from this powder and PDLLA(poly-D,L-lactide acid) were implanted into the femoral holes and the femoral muscle sacs of rats respectively.Normal micron-nacre powder and the artificial bones made from this powder and PDLLA were implanted as control group,and blank group was set up without implanting anything.X-ray photography was performed immediately and at 2,4 and 8 weeks after operation.The animals were injected with tetracycline for fluorescent mark before being killed.Then,the gross specimens,histological and SEM(scanning electron microscope) observations were performed.[Result]All the observations showed that nano-nacre powder degraded faster than micron-nacre powder,meanwhile,the bone defect recovery was the fastest in this group.Both of the composite artificial bones made from those two kinds of nacre powder had the good connection with the adjacent tissue.[Conclusion]The degradation of nano-nacre powder is faster than that of micron-nacre powder in vivo,and it can promote the growing of new bone.Nano-nacre composite artificial bone also has good biocompatibility.It is a kind of better bioactive degradable material.