Oral administration of artemisinin nanospheres alleviates inflammation in mice with spontaneous ulcerative colitis / 细胞与分子免疫学杂志

Objective To investigate the anti-inflammatory effect of artemisinin (ART) encapsulated by β-lactoglobulin (BLG) nanoparticles on Winnie spontaneous ulcerative colitis mouse model. Methods BLG-ART nanoparticles were prepared and their effects on the solubility and stability of ART were evaluated. A mouse model of colitis induced by dextran sulfate sodium (DSS) was used to compare the therapeutic effects of artemisinin (ART) administered by direct gavage and artemisinin encapsulated by β-lactoglobulin nanoparticles (BLG-ART) administered by gavage. Winnie mice were randomly divided into blank group, ART group and BLG-ART group. Mice in the ART group were given 50 mg/kg ART by gavage; mice in the BLG-ART group were given the same dose of BLG-ART nanoparticle PBS dispersion by gavage; mice in the blank group were given the same amount of PBS by gavage, for 16 days. The body mass and disease activity index (DAI) of each group of mice were measured. HE staining was used to observe the pathological changes of mouse intestinal tissue, and real-time quantitative PCR was used to detect the mRNA expression levels of TNF-α, interleukin 1β (IL-1β), IL-10 and IL-17 in mouse colon tissue. Results Compared with the ART group and the blank group, the body mass of the BLG-ART group increased and the DAI decreased after 16-day treatment; the crypt structure of the proximal and distal colon regions of the mice recovered; goblet cell loss decreased; neutrophil infiltration decreased and the mRNA expression levels of pro-inflammatory and anti-inflammatory cytokines were significantly down-regulated. Conclusion ART-BLG can alleviate intestinal inflammation in spontaneous ulcerative colitis mice.

Safety and efficacy of polycaprolactone copolymer nanosphere hydrogel injected into the scalp dermal tissue of rats

BACKGROUND: Currently, dermal fillers need to be 25 µm or larger to reduce in vivo degradation by macrophages. However, the large size of fillers may cause side effects, including interruption of blood flow and nodule formation. Therefore, using rats, we tested a polycaprolactone copolymer hydrogel with nanoscale particles that could maintain a low in vivo degradation rate. METHODS: Thirty-six 6-week-old Sprague-Dawley rats were divided into group A (normal saline), group B (polycaprolactone microsphere filler), and group C (polycaprolactone copolymer nanosphere hydrogel). The corresponding materials were injected into the dermal layer of the scalp of the rats. At 4, 8, and 12 weeks after injection, blood biochemical and kidney and liver histological analyses were performed. Tissues were examined using hematoxylin-eosin staining to observe tissue infiltration of materials. Collagen formation in the dermal tissue of the scalp was observed with Masson trichrome staining and the collagen content was quantified using a soluble collagen assay kit. RESULTS: The histologic examination for organ infiltration showed no abnormal findings. All blood test results were within the normal ranges. The amount of collagen at 12 weeks increased by 1.22 mg/g in group C and by 0.6 mg/g in group B. CONCLUSIONS: The results reveal that the nanosphere complex near the injection site induced collagen formation. Regardless of the sphere size, aggregation of the copolymer prevented macrophage phagocytosis. The polycaprolactone copolymer nanosphere hydrogel was effective for more than 3 months when injected in the scalp dermal tissue of Sprague-Dawley rats and can be used safely.

Sistemas de nanopartículas poliméricas II: estructura, métodos de elaboración, características, propiedades, biofuncionalización y tecnologías de auto-ensamblaje capa por capa (layer-by-layer self-assembly) / Polymeric nanoparticle systems: structure, elaboration methods, characteristics, properties, biofunctionalization and self-assembly layer by layer technologies

Los materiales poliméricos han sido ampliamente investigados para aplicaciones biomédicas, teniendo especial relevancia cuando se encuentran en forma de micro- y nano-partículas. Últimamente se ha ampliado su campo de aplicación al ser conjugados con péptidos y ácidos nucleicos, por lo tanto, el interés en el estudio de este tipo de materiales, así como también en la formulación de nanoestructuras funcionalizadas como materiales, dispositivos y vehículos de transporte de agentes terapéuticos ha aumentado. Las recientes investigaciones en nanosistemas se inspiran en fenómenos naturales que estimulan la integración de señales moleculares y la mimetización de procesos a nivel celular, de tejidos y órganos. Tecnológicamente, la capacidad de obtener nanoestructuras esféricas mediante la combinación de materiales que presenten propiedades distintas a las que ningún otro material individual posee por sí solo, es lo que hace que las nanocápsulas sean particularmente atractivas. Las potenciales ventajas de los sistemas de nanopartículas de tipo polimérico se destacan a lo largo de cada parte de este artículo de revisión. El presente artículo aborda los aspectos más relevantes sobre la estructura, composición y algunos métodos de elaboración de los sistemas nanoparticulados. Además, expone algunos de los trabajos más recientes, centrados en sistemas de nanopartículas basados en polímeros dirigidos a la administración de agentes, publicados en artículos especializados de investigación y revisiones durante los últimos años.

Polymeric materials have been extensively investigated for biomedical applications including micro- and nanoparticles. Modern advances have broadened horizons for application with peptides and nucleic acids. Therefore, interests increased in the formulation of materials, devices and vehicles for transporting therapeutic agents in functionalized nanostructures. Recent nano-systems are inspired by natural phenomena that stimulate the integration of molecular signals and the mimicking of natural cellular processes, at tissue and organ levels. Technologically, the ability to obtain spherical nanostructures, which combine different properties, that no other single material possesses on its own, makes nanocapsules particularly attractive. Potential advantages over polymer nanoparticulate systems are highlighted throughout each part of this review article. Here, we address the most relevant aspects of structure, composition and methods of formulation of nanoparticulate systems. In addition, we outline some of the more recent works focusing on nanosized preparations, based on agent-directed polymers, found in specialized research articles that have emerged in the recent years.

In vitro and in vivo evaluation of nano-based films for buccal delivery of zolpidem

Abstract Insomnia is becoming increasingly prevalent in the world general population. Therapies used by patients include over-the-counter therapies, herbal and dietary supplements, and pharmacological or nonpharmacological treatments. Among these, zolpidem is a pharmacological treatment popularly used for insomnia. Zolpidem is well tolerated and especially efficacious for initiation of sleep, and therefore is effective for the treatment of sleep-onset insomnia. The purpose of the present study was to design and evaluate zolpidem nanoparticle-impregnated buccal films to prolong the duration of its action. Zolpidem nanospheres were prepared by double emulsion solvent evaporation and then loaded into buccoadhesive films (Z1-Z4) comprised of different concentrations of HPMC K100, Eudragit® RL 100, and carbopol 974P. The prepared films were characterized for physicomechanical properties, mucoadhesion, percent hydration, in vitro drug release, ex vivo permeation, and in vivo studies. In vitro drug release was found to depend upon film composition. Ex vivo studies showed that film Z4 had the highest flux. In vivo studies revealed that administration of zolpidem nanosphere-impregnated film enhanced absorption of the drug (p < 0.0001), with a higher peak plasma concentration (52.54 ± 8.22 ng/mL) and area under the curve from time 0 to α (236.00 ± 39.51 ng.h/mL) than oral administration. The increase in time taken to reach the maximum drug concentration (1.5 h) further signifies the potential of these films to provide prolonged drug release. Given these promising results, we concluded that these buccal films could be an alternative route for effective zolpidem delivery.

Cyclodextrin glucanotransferase immobilization onto functionalized magnetic double mesoporous core-shell silica nanospheres

Background Cyclodextrin glucanotransferase (CGTase) from Amphibacillus sp. NPST-10 was covalently immobilized onto amino-functionalized magnetic double mesoporous core-shell silica nanospheres (mag@d-SiO2@m-SiO2-NH2), and the properties of the immobilized enzyme were investigated. The synthesis process of the nanospheres included preparing core magnetic magnetite (Fe3O4) nanoparticles, coating the Fe3O4 with a dense silica layer, followed by further coating with functionalized or non-functionalized mesoporous silica shell. The structure of the synthesized nanospheres was characterized using TEM, XRD, and FT-IR analyses. CGTase was immobilized onto the functionalized and non-functionalized nanospheres by covalent attachment and physical adsorption. Results The results indicated that the enzyme immobilization by covalent attachment onto the activated mag@d-SiO2@m-SiO2-NH2, prepared using anionic surfactant, showed highest immobilization yield (98.1%), loading efficiency (96.2%), and loading capacity 58 µg protein [CGTase]/mg [nanoparticles]) which were among the highest yields reported so far for CGTase. Compared with the free enzyme, the immobilized CGTase demonstrated a shift in the optimal temperature from 50°C to 50-55°C, and showed a significant enhancement in the enzyme thermal stability. The optimum pH values for the activity of the free and immobilized CGTase were pH 8 and pH 8.5, respectively, and there was a significant improvement in pH stability of the immobilized enzyme. Moreover, the immobilized CGTase exhibited good operational stability, retaining 56% of the initial activity after reutilizations of ten successive cycles. Conclusion The enhancement of CGTase properties upon immobilization suggested that the applied nano-structured carriers and immobilization protocol are promising approach for industrial bioprocess for production of cyclodextrins using immobilized CGTase.

Effect of FK506 nanospheres on regeneration of allogeneic nerve after transplant

OBJECTIVE@#To discuss effect of FK506 nanospheres used at different time on the regeneration of allogeneic nerve after transplant.@*METHODS@#Single emulsion-solvent evaporation method (O/W) was adopted to prepare the FK506 nanospheres and the tibial nerve of rats after allogeneic transplantation. FK506 nanospheres were used in group A after operation immediately, in group B in 24 h after operation, and in group C in 3 d after operation while FK506 nanospheres were not used in group D; in the 4th, 8th and 12th week after operation respectively, general observation of transplanted nerves, histological examination, image analysis of myelinated fibers, wet-weight determination of musculi triceps surae, retrogradely labeling of neurons by the fluorescein and electrophysiological comparison of bilateral tibial nerve were carried out.@*RESULTS@#FK506 nanospheres can be degraded and absorbed quickly. The neural regenerations in group A and B were similar, which were both much better than those in group C and D. The difference was statistically significant and so was the difference between group C and D.@*CONCLUSIONS@#Drug release rate of FK506 nanospheres is accordant with the regeneration law of damaged nerves and the local application can promote the regenerations of nerves. The effect would be better if the drug is used in earlier period (within 24 h).

Evaluation of the Verigene Warfarin Metabolism Nucleic Acid Test Kit for the Rapid Detection of CYP2C9 and VKORC1 Polymorphisms

BACKGROUND: Warfarin is a widely used oral agent for anticoagulation therapy. Warfarin has a narrow therapeutic index and a wide variation in the interindividual therapeutic dosage. Recently, genotypes of CYP2C9 and VKORC1 have been found to account for 30-40% of the warfarin dosing variability, and a variety of commercial genotyping assays are being introduced. In this study, we evaluated the Verigene Warfarin Metabolism Nucleic Acid test (Verigene Warfarin assay; Nanosphere, USA) for its accuracy and clinical utility in genotyping CYP2C9*2, CYP2C9*3, and VKORC1 1173C>T. METHODS: We compared the Verigene Warfarin assay with direct sequencing for accuracy in determining the genotypes of CYP2C9*2, CYP2C9*3, and VKORC1 1173C>T using 50 patient samples and 3 commercial DNA samples with known genotypes. The method was also evaluated for turn-around time, hands-on time, and feasibility. RESULTS: The Verigene Warfarin assay demonstrated 100% accuracy for identifying CYP2C9*2, CYP2C9*3, and VKORC1 1173C>T. The turn-around time and hands-on time were 3 hr and 2 min, respectively. The no-call error rate at first attempt was estimated to be 2%. CONCLUSIONS: The Verigene Warfarin assay provides rapid and accurate genotype results. Considering there are only a few steps requiring manual intervention, it would be feasible to implement this assay even in clinical laboratories that lack considerable expertise in molecular diagnostics.

A Case of Warfarin-Induced Bleeding in a Patient with CYP2C9 and VKORC1 Gene Polymorphism, Detected by a Point-of-Care Gene Test Device / 대한내과학회지

A 69-year-old female Korean patient was initially prescribed warfarin for the prevention of systemic thromboembolism due to atrial fibrillation. One month later, multiple bruises and subcutaneous hematomas were evident, and laboratory testing revealed a prolonged prothrombin time (PT) of > 106s. After admission, the PT was corrected via fresh frozen plasma transfusion and intravenous vitamin K infusion. We sought to determine the cause of the PT prolongation, suspecting that genetic cause may have had an effect on the variation in the warfarin dose requirement. A point-of-care gene test device (Verigene(R) system; Nanosphere, Northbrook, IL) revealed CYP2C9*1/*3 heterozygosity and a VKORC1 A/A single nucleotide polymorphism. Although it is well established that CYP2C9 or VKORC1 gene polymorphisms can influence warfarin dose requirements, they can be easily neglected, with detrimental outcomes. Through our experience with CYP2C9 and VKORC1 polymorphism causing bleeding complications during warfarin treatment, we aim to emphasize the importance of pharmacogenetic testing to avoid this potential oversight.

Continued sustained release of VEGF by PLGA nanospheres modified BAMG stent for the anterior urethral reconstruction of rabbit

OBJECTIVE@#To study the biocompatibility and neovascularization of the PLGA nanospheres wrapped with vascular endothelial growth factor (VEGF), which can improve bladder acellular matrix graft (BAMG) with local continuous release of VEGF.@*METHODS@#A total of 18 rabbit model (length of stenosis: 3 cm) with anterior urethral stricture were used as experimental animals and divided into three groups. Group A as the control group: Simple BAMG scaffold materials for urethral reconstruction. Group B as the blank group: PLGA microspheres modified BAMG for urethral reconstruction. Group C: PLGA conjugated with VEGF and modified BAMG for the urethral reconstruction. All rabbits underwent urethral angiography after 7 days, 15 days, 1 month and 3 months after the operation, and one rabbit in each group was sacrificed to be prepared for the organization histologic examination, HE staining, masson staining, CD31, 34 and a-SAM immunohistochemical detection in the repaired sites.@*RESULTS@#In group A, significant urethral restenosis occurred in two rabbits after 15 days of the operation, HE and masson staining showed a lot of collagen arranged in the repaired sites, and there were a large number of inflammatory cell infiltration, and there were also CD31, 34 in the repaired sites. a-SAM microvascular tag count showed a small amount of microvascular; Group B showed anastomotic restenosis, HE and masoon staining showed inflammatory cell infiltration and collagen deposition; Group C: urethrography showed lumen patency. There were a small amount of inflammatory cell infiltration after 7 and 15 days after the operation, and there were also CD31, 34 in the repaired sites. The a-SAM microvascular tag count showed many microvascular. And the difference was significant.@*CONCLUSIONS@#Anterior urethral reconstruction with sustained-release of VEGF by PLGA nanospheres modified BAMG stents can reduce postoperative restenosis. It can also reduce collagen deposition and scar formation, promote angiogenesis of the repair tissue; therefore it in valuable in the tissue-engineered urethral reconstruction.

The effect of modified bone morphogenetic protein-2 polylactic acid nanospheres sustained-release system on promoting mandibular defect repair / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the effect of modified bone morphogenetic protein-2 polylactic acid nanospheres (BMP-2-PLA-Ns) sustained-release system on rabbit mandibular defect repair.</p><p><b>METHODS</b>The polylactic acid s nanospheres (PLA-Ns) and BMP-2-PLA-Ns were prepared by ultrasonic emulsification after graft polymerization. Forty-five rabbits were randomly divided into 3 groups: Blank group, PLA-Ns gel group(control group), and BMP-2-PLA-Ns gel group (experimental group). The rabbit mandibular defect models were established. The defect area of control group was implanted with PLA-Ns gel, meanwhile, the experimental group was implanted with BMP-2-PLA-Ns gel, the blank group experienced no special handling. Rabbits were killed in 1, 2, 4 weeks after operation and the iconography, hematine eosin(HE) staining and PCNA immunohistochemistry were used to detect the reparative effect on rabbit mandible defects.</p><p><b>RESULTS</b>Image observation showed that bone defect repair in the experimental group was well and the shadow was not obvious. Better repair effect was seen compared with the control group and blank group. HE staining showed that the experimental group and the control group had a large number of neovascularization and secondary callus formation, callus in experimental group was obviously higher than that of control group and blank group. Immunohistochemical observation showed that the experimental group's PCNA positive chondrocytes were more than those in the control group and the blank group in the first 2 weeks; all groups of PCNA positive cells were rare in the fourth week, PCNA positive expression rate of the fourth week was lower than that of the first 2 weeks.</p><p><b>CONCLUSION</b>The modified BMP-2-PLA-Ns sustained-release system promotes mandibular defect repair obviously.</p>

Nanotechnology in ligature-induced periodontitis: protective effect of a doxycycline gel with nanoparticules

OBJECTIVES: The aim of this study was to test the efficacy of a locally applied 8.5 percent nanostructured doxycycline (DOX) gel in preventing alveolar bone loss in experimental periodontal disease (EPD) in rats by using the tapping mode atomic force microscopy (AFM). MATERIAL AND METHODS: EPD was induced in 24 Wistar rats. Animals were treated with the doxycycline gel topically, immediately after EPD induction, and 3 times a day during 11 days. Four groups (n=6) were formed as follows: Naïve group (animals not subjected to EPD nor treated); non-treated (NT) group (animals subjected to EPD, but not treated); vehicle gel (VG) group (animals subjected to EPD and treated with topical gel vehicle); and DOX group (test group): animals subjected to EPD and treated with the 8.5 percent DOX gel. In order to investigate topographical changes in histological sections, a novel simple method was used for sample preparation, by etching sections from paraffin-embedded specimens with xylol. RESULTS: Comparing the AFM images, several grooves were observed on the surface of the alveolar bone and other periodontal structures in the NT and VG groups, with significantly greater depths when compared to the DOX group (p<0.05). CONCLUSIONS: Periodontal structures were brought into high relief confirming to be a simple and cost-effective method for AFM imaging with ultrastructural resolution. The doxycycline gel was able to afford periodontal surface preservation, with flatter grooves.

Comparison of in vitro release behavior of proanthocyanidins flexible nanoliposomes and general nanoliposomes / 中国中药杂志

<p><b>OBJECTIVE</b>To prepare flexible proanthocyanidins nanoliposomes, and explore the in vitro release behavior of proanthocyanidins flexible nanoliposomes and general nanoliposomes.</p><p><b>METHOD</b>Flexible proanthoeyanidins nanoliposomes were prepared proanthocyanidins using a film dispersion method, characterized by transmission electron microscope, and the in vitro release action was studied in different dissolution mediums using dynamic dialyse method with the content of total phenol as index.</p><p><b>RESULT</b>The in vitro release of both proanthocyanidins flexible nanoliposomes and general nanoliposomes were in accordance with Weibull distribution.</p><p><b>CONCLUSION</b>Proanthocyanidins flexible nanoliposomes without pressure had similar in vitro release behavior with general nanoliposomes.</p>

Preparation and release exam of magnetic chitosan nano-spheres of doxorubicin / 生物医学工程学杂志

Magnetic chitosan (CS) nano-spheres were prepared by the modified suspension cross-linking technique. The results demonstrated that the magnetic drug nano-spheres are mainly spherical in form with a size of 200 to 800 nm, and show good magnetic responsivity. Here, Doxorubicin was used as exam drug. Glutaraldehyde connects Doxorubicin to CS by the chemical bond (-N = C-), and the drug content is in range of 1% to 15% (w/w). The chemical bond is broken depending on pH, so pH is the important factor for the release of doxorubicin. The doxorubicin release was 22.0%, 13.4%, and 4.1% in the space of 7d, when pH was 1, 2, 4. So the nano-spheres are pH-sensitive magnetic targeting drug micro-spheres.

Antitumor effect of nanospheres coupled with the anti-human liver cancer monoclonal antibody HAb18 / 南方医科大学学报

<p><b>OBJECTIVE</b>To prepare nanospheres coupled with the anti-human liver cancer monoclonal antibody HAb18 and evaluate its immunoreactivity and antitumor effects.</p><p><b>METHODS</b>The nanosphere coupled with the antibody was prepared by intermolecular cross-linking the anti-human liver cancer monoclonal antibody, HAb18, with human serum albumin nanospheres containing ADM [termed HAS(ADM)-NS] via a new hetero-bifunctional cross-linker SPDP. Condensation test and immunofluorescence assay were used to evaluate the immunoreactivity of the nanospheres, and specific binding of HAb18-HAS(ADM)-NS with liver cancer cell line SMMC-7721 was observed with optical and electron microscopes. The specific cytotoxic effects on the target cells were evaluated in vitro by MTT assay. HAb18-HAS(ADM)-NS, HAS(ADM)-NS and ADM were injected separately into nude mice bearing human liver carcinoma to evaluate the inhibitory activity of HAb18-HAS(ADM)-NS in vivo.</p><p><b>RESULTS</b>The immunoreactivity of HAb18-HAS(ADM)-NS was well preserved. HAb18-HAS(ADM)-NS could bind specifically with the SMMC-7721 cells. The IC(50) of HAb18-HAS(ADM)-NS against SMMC-7721 cells was 44.6 microg/ml, lower than that of HAS(ADM)-NS (345.5 microg/ml) and ADM (365.5 microg/ml). The inhibition rate of HAb18-HAS(ADM)-NS on the growth of liver cancer xenografts was significantly higher than that of HAS(ADM)-NS and ADM (P<0.001).</p><p><b>CONCLUSION</b>HAb18-HAS(ADM)-NS has immunoreactivity and can actively and specifically target the liver cancer cells. The antitumor activity of HAb18-HAS(ADM)-NS is significantly higher than that of HAS(ADM)-NS and ADM.</p>

PLGA nanospheres loaded with autoclaved leishmania major [ALM] and CPG-ODN: preparation and in vitro characterization

Several antigens, adjuvants and delivery systems have been evaluated for induction of protective immune responses against Leishmaniasis, but most of them have been inefficient. In this study, PLGA nanospheres as antigen delivery system CpG-ODN as an immunoadjuvant for increasing the immune responses against Autoclaved Leishmania major [ALM] were prepared and characterized. PLGA nanospheres prepared by a double-emulsion [W/O/W] technique. The internal aqueous phase contained ALM and CpG-ODN, while the oily phase contained the solution of PLGA in dichloromethan and the external aqueous phase was PVA 7.5% [WIV] solution. Particulate characteristics were studied by scanning electron microscopy and particle size analysis. The encapsulation efficiency was determined by Lowry method for ALM and UV spectroscopy at 260 nm for CpG-ODN. The release profiles of antigen and CpG-ODN from nanospheres evaluated for one week. Nanospheres were spherical in shape, having smooth surfaces. Mean diameters for blank and ALM + CpGODN loaded nanospheres recorded as 302 +/- 129 and 333 +/- 128 nm respectively. Also, the encapsulation efficiencies of ALM and CpG-ODN were 71.6 +/- 8.8 and 49.1 +/- 2.4%, respectively. Evaluation of the release profiles of ALM and CpG-ODN from nanospheres showed that 44.8 +/- 0.8% of ALM and 29.5 +/- 0.2% of CpGODN released from nanospheres in one week. The prepared nanospheres with desirable size, encapsulation efficiency, and slow rate of release, had acceptable features for future in vivo studies

Preparation and characterization of PLGA nanospheres encapsulated with autoclaved leishmania major [ALM] and quillaja saponin

Several antigens, adjuvants and delivery systems have been evaluated for induction of protective immune responses against leishmaniasis, but have mostly been inefficient. In this study, poly [d,l-lactide-co-glycolide] [PLGA] nanospheres as antigen delivery system and Quillaja saponins [QS] as an immunoadjuvant have been used to increase the immune responses against Autoclaved Lieshmania major [ALM]. PLGA nanospheres were prepared using a double emulsion [W/O/W] technique. The internal aqueous phase contained ALM and saponin, while the oily phase contained the solution of PLGA in dichloromethane and the external aqueous phase was polyvinylalcohol [PVA] 7.5% [W/V] solution. Particulate characteristics were studied by scanning electron microscope and particle size analyzer. The encapsulation efficiency was determined by Lowry method and the release profile of antigen and saponin from nanospheres was evaluated for one week. Nanospheres were spherical in shape having smooth surfaces. Mean diameters for nanospheres loaded with ALM and ALM+QS were 300 +/- 123 nm and 294 +/- 106 nm respectively. Encapsulation efficiencies for ALM and QS were found 71 +/- 14.8% and 55.8 +/- 23.1%, respectively. Evaluation of the release profiles of ALM and QS from nanospheres in one week showed that 44.8 +/- 0.8% of ALM and 29.5 +/- 0.21% of QS had been released from nanospheres. In conclusion, the prepared nanospheres with desirable size, encapsulation efficiency, and slow rate of release, had acceptable features for future in vivo studies

Preparation and characterization of ampicillin loaded ethylcellulose nanospheres / 生物医学工程学杂志

Ampicillin sodium was embeded in ethylcellulose (EC) nanospheres made of low-molecular-weight EC. Low-molecular-weight EC was attained with ethylcellulose being degraded by 34% (w/w) nitric acid; Fourier transform infrared (FTIR) spectroscopy, 13C-NMR, element analysis confirmed that the basic structure and major properties of low-molecular-weight EC maintained agreement with those of undegraded EC except that the polymerization degree of EC decreased. Wide-angle X-ray diffraction demonstrated that the crystallinity of degraded EC decreased. Ampicillin sodium loaded EC nanospheres were characterized by transmission electron microscopy, FTIR and in vitro drug release. Molecular weight of EC would affect the size of nanospheres, distribution and drug encapsulation efficiency. Drug loaded nanospheres resulted in the drug control release in 3-10 hours.

Development and in-vitro Evaluation of a Topical Drug Delivery System Containing Betamethazone Loaded Ethyl Cellulose Nanospheres

PURPOSE : Lipid nanospheres are used for the passive targeting of cosmetic agents to skin; thereby achieving major benefits such as reduction of total dose and avoidance of systemic absorption. The present study was carried out to exploit the feasibility of using polymeric nanospheres as an alternative and cheaper carrier for targeting corticosteroids to the skin. METHODS: Nanospheres were prepared from ethyl cellulose by a modified method of desolvation and cross linking. The drug betamethazone was incorporated into nanospheres and the drug : polymer ratio was evaluated to determine the carrier capacity of the polymer. In vitro release studies of drug-loaded nanospheres were carried out by the centrifugal ultrafiltration method. The kinetics of release was determined and fitted to an empirical equation. The release of drug from drug-loaded nanospheres dispersing in a conventional cream was evaluated. A comparative in vitro diffusion study was carried out between a commercial brand of cream and the cream incorporating nanospheres. RESULTS: Formulation of nanospheres of betamethazone by a modified method produced discrete particles. Studies on drug : polymer ratio showed a linear relationship between drug concentration and percentage of loading. The in vitro release of drug-loaded nanospheres was found to be first order. The comparative in vitro diffusion study between the commercial cream and the formulated cream showed a marked reduction in release rate from nanospheres-bound cream. CONCLUSION : Formulated topical cream containing nanospheres of betamethazone was found to be a potential dermal delivery system for sustaining the release of the drug