ABSTRACT
The synthesis of drug delivery systems based on hollow mesoporous silica nanoparticles (MSNs) is still a major challenge. In this work, the hollow hybrid MSNs were successfully prepared by cetyltrimethylammonium bromide-directed sol-gel process and one-step hydrothermal treatment process. The hollow hybrid MSNs had hybrid ethane-bridged frameworks with the uniform particle size (250 nm) and mesoporous pore diameter (3.7 nm). The polyacrylic acid (PAA) encapsulated drug delivery system based on hollow hybrid MSNs was prepared by using silanization, surface modification, doxorubicin hydrochloride (DOX) loading, and PAA coating. Drug encapsulation and release behavior at different temperatures and pH were studied by using DOX as a model guest molecule. The results displayed that the modified hollow ethane-bridged MSNs possessed good biocompatibility and excellent thermal/pH-dual-sensitive drug release property. This novel thermal/pH-sensitive drug delivery system based on hollow ethane-bridged MSNs has the advantages of feasible synthesis, no cytotoxicity, and good drug loading capacity, which may have potential applications in the anticancer therapy.
Subject(s)
Nanoparticles , Nanospheres , Acrylic Resins , Antibiotics, Antineoplastic , Doxorubicin , Drug Carriers , Drug Delivery Systems , Hydrogen-Ion Concentration , Porosity , Silicon , Silicon DioxideABSTRACT
The synthesis of drug delivery systems based on surface-modified mesoporous silica hollow structures remains a huge challenge. In this paper, we have obtained hollow mesoporous silica nanoparticles (MSNs) by surfactant directed sol-gel assisted hydrothermal treatment. The MSNs have the inorganic-organic hybrid frameworks with uniform diameter distribution (260 nm), and their specific surface area, mesoporous size and pore volume are 540 m2 g-1, 3.7 nm, 0.58 cm3 g-1, respectively. It was proved that the preparation of hollow ethane-bridged nanospheres with two silicon source was due to the high crosslinking of the silicone interface and hydrothermal treatment, providing a new approach for the study of drug-loaded and controlled release behavior. Based on the synthesis of MSNs, MSNs were modified by methacryloxy propyl trimethoxyl silane (MPS) on the surface of MSNs. Then N-isopropylacryamide (NIPAM) and acrylic acid (AA) were grafted onto the surface of modified MSNs. The hollow ethane-bridged PNA-MSNs (poly (NIPAM-co-acrylic acid)-MSNs) with two silicon source were prepared successfully. Due to their distinctive hollow structure, PNA-MSNs demonstrated high drug encapsulation efficiency (70.4% ± 2.9%). The experiment results proved that the modified hollow nanoparticles not only had good biocompatibility and stability, but also possessed pH-/thermal-dual responsiveness in drug release.
Subject(s)
Acrylamides/chemistry , Acrylates/chemistry , Drug Carriers , Nanoparticles/chemistry , Silanes/chemistry , Silicon Dioxide/chemistry , Antibiotics, Antineoplastic/chemistry , Antibiotics, Antineoplastic/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Doxorubicin/chemistry , Doxorubicin/pharmacology , Drug Compounding/methods , Drug Liberation , HeLa Cells , Humans , Kinetics , Nanoparticles/ultrastructure , Particle Size , Phase Transition , Porosity , Surface PropertiesABSTRACT
BACKGROUND: Host genetic factors may play a role in the occurrence and progress of SARS-Cov infection. This study was to investigate the relationship between tumor necrosis factor (TNF)-alpha gene polymorphisms with the occurrence of SARS-CoV infection and its role in prognosis of patients with lung interstitial fibrosis and femoral head osteonecrosis. METHODS: The association between genetic polymorphisms of TNF-alpha gene and susceptibility to severe acute respiratory syndromes (SARS) was conducted in a hospital-based case-control study including 75 SARS patients, 41 health care workers and 92 healthy controls. Relationships of TNF-alpha gene polymorphisms with interstitial lung fibrosis and femoral head osteonecrosis were carried out in two case-case studies in discharged SARS patients. PCR sequencing based typing (PCR-SBT) method was used to determine the polymorphisms of TNF-alpha gene in locus of the promoter region and univariate logistic analysis was conducted in analyzing the collected data. RESULTS: Compared to TT genotype, the CT genotype at the -204 locus was found associated with a protective effect on SARS with OR(95%CI) of 0.95(0.90-0.99). Also, TT genotype, CT and CC were found associated with a risk effect on femoral head necrosis with ORs(95%CI) of 5.33(1.39-20.45) and 5.67(2.74-11.71), respectively and the glucocorticoid adjusted OR of CT was 5.25(95%CI 1.18-23.46) and the combined (CT and CC) genotype OR was 6.0 (95%CI 1.60-22.55) at -1031 site of TNF-alpha gene. At the same time, the -863 AC genotype was manifested as another risk effect associated with femoral head necrosis with OR(95%CI) of 6.42(1.53-26.88) and the adjusted OR was 8.40(95%CI 1.76-40.02) in cured SARS patients compared to CC genotype. CONCLUSION: SNPs of TNF-alpha gene of promoter region may not associate with SARS-CoV infection. And these SNPs may not affect interstitial lung fibrosis in cured SARS patients. However, the -1031CT/CC and -863 AC genotypes may be risk factors of femoral head necrosis in discharged SARS patients.
