Controlled Release Characteristics of PLA-Pluronic-PLA Nano-Sized Vesicles In Vitro

2013 ◽  
Vol 785-786 ◽  
pp. 493-497
Author(s):  
Yu Ping Li ◽  
Li Zhen Sun ◽  
Xiang Yuan Xiong ◽  
Zi Ling Li ◽  
Ting Kang Xing ◽  
...  
Keyword(s):  
Controlled Release ◽  
Protein Delivery ◽  
Phosphate Buffer Solution ◽  
Entrapment Efficiency ◽  
Poly Lactic Acid ◽  
Oral Insulin ◽  
Buffer Solution ◽  
The Mean ◽  
The Stability

In the present study, controlled release characteristics of new nanosized PLA-Pluronic-PLA block copolymer vesicles comprising of amphiphilic poly (lactic acid) (PLA) and Pluronic block copolymers (PEO-PPO-PEO) have been evaluated as an oral insulin carrier. The mean size of vesicles was 78 nm for PLA-F127-PLA and 165 nm for PLA-P85-PLA copolymer. The mean insulin entrapment efficiency was 59.6% for PLA-P85-PLA and 26.4% for PLA-F127-PLA. The in vitro release characteristics of insulin from vesicles exhibited an initial burst in the range of pH 1.2-7.4 dissolution mediums. The presence of PLA-Pluronic-PLA vesicles improved the stability of insulin in the gastrointestinal fluids than that of the phosphate buffer solution (PBS) of insulin. More importantly, the released insulin from the vesicles maintained their biological activity. The results from this studies demonstrated that biodegradable PLA-Pluronic-PLA can self-assemble with insulin, form insulin-encapsulated vesicles, and is good carrier materials for oral insulin/protein delivery.

scholarly journals Performance of Polyester-Based Electrospun Scaffolds under In Vitro Hydrolytic Conditions: From Short-Term to Long-Term Applications

Nanomaterials ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 786 ◽  
Author(s):  
Oscar Gil-Castell ◽  
José David Badia ◽  
Jordi Bou ◽  
Amparo Ribes-Greus
Keyword(s):  
Molar Mass ◽  
Pure Water ◽  
Phosphate Buffer Solution ◽  
Short Term ◽  
Buffer Solution ◽  
Electrospun Scaffolds ◽  
The Stability ◽  
Short Time

The evaluation of the performance of polyesters under in vitro physiologic conditions is essential to design scaffolds with an adequate lifespan for a given application. In this line, the degradation-durability patterns of poly(lactide-co-glycolide) (PLGA), polydioxanone (PDO), polycaprolactone (PCL) and polyhydroxybutyrate (PHB) scaffolds were monitored and compared giving, as a result, a basis for the specific design of scaffolds from short-term to long-term applications. For this purpose, they were immersed in ultra-pure water and phosphate buffer solution (PBS) at 37 °C. The scaffolds for short-time applications were PLGA and PDO, in which the molar mass diminished down to 20% in a 20–30 days lifespan. While PDO developed crystallinity that prevented the geometry of the fibres, those of PLGA coalesced and collapsed. The scaffolds for long-term applications were PCL and PHB, in which the molar mass followed a progressive decrease, reaching values of 10% for PCL and almost 50% for PHB after 650 days of immersion. This resistant pattern was mainly ascribed to the stability of the crystalline domains of the fibres, in which the diameters remained almost unaffected. From the perspective of an adequate balance between the durability and degradation, this study may serve technologists as a reference point to design polyester-based scaffolds for biomedical applications.

In Vitro Biodegradability of Poly(lactic Acid)/Hydroxyapatite Biocomposites Prepared by Solvent-Blending Technique

2012 ◽  
Vol 626 ◽  
pp. 631-635 ◽  
Author(s):  
Mujtahid Kaavessina ◽  
Fitriani Khanifatun ◽  
Imtiaz Ali ◽  
Saeed M. Alzahrani
Keyword(s):  
Lactic Acid ◽  
Hydrolytic Degradation ◽  
Phosphate Buffer Solution ◽  
Weight Fraction ◽  
Poly Lactic Acid ◽  
Buffer Solution ◽  
Before And After ◽  
Micro Holes ◽  
Thermal Stability Of

Poly (lactic acid) was solvent-blended and formed as thin ribbons with different weight fraction of hydroxyapatite, namely 5, 10 and 20wt%. In-vitro biodegradability of biocomposites was performed in phosphate buffer solution (PBS) at 37°C. The presence of hydroxyapatite tended to increase biodegradability of poly (lactic acid) in its biocomposites. Thermal stability of biocomposites was always higher than that neat poly (lactic acid) either before and after hydrolytic degradation tests. After biodegradation tests, some micro-holes and cracks were appeared in the surface morphology of biocomposites as well as the increasing crystallinity occurred.

scholarly journals Encapsulation of Polyphenols from Lycium barbarum Leaves into Liposomes as a Strategy to Improve Their Delivery

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1938
Author(s):  
Ramona-Daniela Păvăloiu ◽  
Fawzia Sha’at ◽  
Georgeta Neagu ◽  
Mihaela Deaconu ◽  
Corina Bubueanu ◽  
...  
Keyword(s):  
Particle Size ◽  
Phosphate Buffer ◽  
Phosphate Buffer Solution ◽  
Entrapment Efficiency ◽  
Cytoprotective Effect ◽  
Buffer Solution ◽  
Lycium Barbarum ◽  
Burst Effect ◽  
Pharmaceutical Applications

This study is focused on the encapsulation of polyphenols from Lycium barbarum leaves into liposomes as a strategy to improve their delivery. Liposomes loaded with Lycium barbarum leaves extract were obtained and characterized for particle size, polydispersity, entrapment efficiency, and stability. Liposomes presented entrapment efficiency higher than 75%, nanometric particle size, narrow polydispersity, and good stability over three months at 4 °C. The liposomes containing Lycium barbarum offered a slower release of polyphenols with attenuated burst effect compared with the dissolution of free Lycium barbarum extract in phosphate buffer solution at pH 7.4. Moreover, an in vitro pretreatment of 24 h with loaded liposomes showed a cytoprotective effect against H2O2-induced cytotoxicity on L-929 mouse fibroblasts cells. These preliminary findings imply that liposomes could be successfully employed as carriers for polyphenols in pharmaceutical applications.

In vitro ovicidal activity of poly lactic acid curcumin-nisin co-entrapped nanoparticle against Fasciola spp. eggs and its reproductive toxicity

2018 ◽  
Vol 29 (1) ◽  
pp. 73-79 ◽  
Author(s):  
Oyetunde Oyeyemi ◽  
Odunayo Adegbeyeni ◽  
Ifeoluwa Oyeyemi ◽  
Jairam Meena ◽  
Amulya Panda
Keyword(s):  
Reproductive Toxicity ◽  
Entrapment Efficiency ◽  
Negative Control ◽  
Poly Lactic Acid ◽  
Sperm Cells ◽  
Ovicidal Activity ◽  
Egg Hatching ◽  
The Mean

AbstractBackground:Curcumin and nisin have been widely reported for their antibacterial and anticancer potency. However, their therapeutic applications are hampered by several factors, which necessitate their development into nanosize ranges for improved delivery and activities. Their incorporation into a single nanosynthesized form may suggest desirable efficacy on parasites. The aim of the study was to assess the ovicidal activity of the curcumin-nisin polylactic acid (PLA) entrapped nanoparticle on theFasciolaeggs and its reproductive toxicity.Methods:The nanoparticle was formulated by double emulsion method. The eggs of the adultFasciolaspp. were exposed to different concentrations (0.3125–5 mg/mL) of the nanoparticle to monitor hatchability. Mice were exposed to 0.5 mL of the formulated drug at varying concentrations (10–20 mg/kg) and then sacrificed for sperm morphology assay.Results:The mean particle size, polydispersity index, and drug entrapment efficiency of the formulated drug were 288.4±24.3 nm, 0.232, and 51.7%, respectively. The highest nanoparticulate concentration (5 mg/mL) showed the least percentage egg hatching (41.7%) compared with the other treatment groups and positive control (albendazole) (45.1%). The aberrations observed in sperm cells were not concentration-dependent and no significant differences were observed in the mean aberrations between the nanoparticulate drug-exposed groups and the negative control (p>0.05).Conclusions:The results confirmed the ovicidal activity of the curcumin-nisin nanoparticulate drug against theFasciolaspecies. The formulation also showed no toxicity to sperm cells. More robust studies on anti-fascioliasis activity of the drug on adultFasciolaspp. andin vivoandin vitrotoxicity studies are recommended.

scholarly journals Entrapment of the Fastest Known Carbonic Anhydrase with Biomimetic Silica and Its Application for CO2 Sequestration

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2452
Author(s):  
Chia-Jung Hsieh ◽  
Ju-Chuan Cheng ◽  
Chia-Jung Hu ◽  
Chi-Yang Yu
Keyword(s):  
Carbonic Anhydrase ◽  
High Activity ◽  
Co2 Sequestration ◽  
Residual Activity ◽  
Entrapment Efficiency ◽  
Free Form ◽  
Uncatalyzed Reaction ◽  
The Stability ◽  
Time Required

Capturing and storing CO2 is of prime importance. The rate of CO2 sequestration is often limited by the hydration of CO2, which can be greatly accelerated by using carbonic anhydrase (CA, EC 4.2.1.1) as a catalyst. In order to improve the stability and reusability of CA, a silica-condensing peptide (R5) was fused with the fastest known CA from Sulfurihydrogenibium azorense (SazCA) to form R5-SazCA; the fusion protein successfully performed in vitro silicification. The entrapment efficiency reached 100% and the silicified form (R5-SazCA-SP) showed a high activity recovery of 91%. The residual activity of R5-SazCA-SP was two-fold higher than that of the free form when stored at 25 °C for 35 days; R5-SazCA-SP still retained 86% of its activity after 10 cycles of reuse. Comparing with an uncatalyzed reaction, the time required for the onset of CaCO3 formation was shortened by 43% and 33% with the addition of R5-SazCA and R5-SazCA-SP, respectively. R5-SazCA-SP shows great potential as a robust and efficient biocatalyst for CO2 sequestration because of its high activity, high stability, and reusability.

scholarly journals Formulation and development of metformin-loaded microspheres using Khaya senegalensis (Meliaceae) gum as co-polymer

2020 ◽  
Vol 6 (1) ◽  
Author(s):  
Chukwuebuka H. Ozoude ◽  
Chukwuemeka P. Azubuike ◽  
Modupe O. Ologunagba ◽  
Sejoro S. Tonuewa ◽  
Cecilia I. Igwilo
Keyword(s):  
Controlled Release ◽  
Sodium Alginate ◽  
Release Kinetics ◽  
Drug Carrier ◽  
In Vitro Release ◽  
Entrapment Efficiency ◽  
Metformin Hydrochloride ◽  
Scanning Calorimetry ◽  
Khaya Senegalensis

Abstract Background Khaya gum is a bark exudate from Khaya senegalensis (Maliaecae) that has drug carrier potential. This study aimed to formulate and comparatively evaluate metformin-loaded microspheres using blends of khaya gum and sodium alginate. Khaya gum was extracted and subjected to preformulation studies using established protocols while three formulations (FA; FB and FC) of metformin (1% w/v)-loaded microspheres were prepared by the ionic gelation method using 5% zinc chloride solution as the cross-linker. The formulations contained 2% w/v blends of khaya gum and sodium alginate in the ratios of 2:3, 9:11, and 1:1, respectively. The microspheres were evaluated by scanning electron microscopy, Fourier transform-infrared spectroscopy, differential scanning calorimetry, entrapment efficiency, swelling index, and in vitro release studies. Results Yield of 28.48%, pH of 4.00 ± 0.05, moisture content (14.59% ± 0.50), and fair flow properties (Carr’s index 23.68 ± 1.91 and Hausner’s ratio 1.31 ± 0.03) of the khaya gum were obtained. FTIR analyses showed no significant interaction between pure metformin hydrochloride with excipients. Discrete spherical microspheres with sizes ranging from 1200 to 1420 μm were obtained. Drug entrapment efficiency of the microspheres ranged from 65.6 to 81.5%. The release of the drug from microspheres was sustained for the 9 h of the study as the cumulative release was 62% (FA), 73% (FB), and 80% (FC). The release kinetics followed Korsmeyer-Peppas model with super case-II transport mechanism. Conclusion Blends of Khaya senegalensis gum and sodium alginate are promising polymer combination for the preparation of controlled-release formulations. The blend of the khaya gum and sodium alginate produced microspheres with controlled release properties. However, the formulation containing 2:3 ratio of khaya gum and sodium alginate respectively produced microspheres with comparable controlled release profiles to the commercial brand metformin tablet.

Bacterial chemotaxis to fungal propagules in vitro and in soil

1983 ◽  
Vol 29 (9) ◽  
pp. 1104-1109 ◽  
Author(s):  
D. K. Arora ◽  
A. B. Filonow ◽  
J. L. Lockwood
Keyword(s):  
Sandy Loam ◽  
Phosphate Buffer Solution ◽  
Bacterial Chemotaxis ◽  
Macrophomina Phaseolina ◽  
Buffer Solution ◽  
Erwinia Herbicola ◽  
Cochliobolus Victoriae ◽  
Fungal Propagules ◽  
Loam Soil

Erwinia herbicola, Pseudomonas fluorescens, and P. putida were strongly attracted in vitro to substances exuded by conidia of Cochliobolus victoriae and sclerotia of Macrophomina phaseolina, but not to phosphate buffer solution. Numbers of bacteria attracted to propagules of C. victoriae or M. phaseolina in an unsterilized sandy loam soil were significantly (P = 0.05) greater than background populations occurring in soil saturated with buffer. Chemotactic response was greater to C. victoriae than to M. phaseolina both in vitro and in soil. Results suggest that living fungal propagules may act as attractants for motile bacteria in soil.

Surface Morphological Changes Accompanying Dissolution of Bioactive Glass: Effect of Residual Stress

2008 ◽  
Vol 47-50 ◽  
pp. 1302-1306 ◽  
Author(s):  
John A. Nychka ◽  
Ding Li
Keyword(s):  
Residual Stress ◽  
Residual Stresses ◽  
Bioactive Glass ◽  
Morphological Changes ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Mechanochemical Effect ◽  
Dissolution Behaviour ◽  
Glass Surfaces

We report our observations concerning the time evolution of surface morphology occurring during the in vitro immersion of bioactive glass surfaces in contact with phosphate buffer solution. We compare regions under intentionally produced residual stresses via micro-indentation to those where no indentation was performed. The sign of the residual stress is shown to be important for predicting dissolution behaviour; compression retards dissolution, whereas tension enhances dissolution. We analyze our results with a simple model for the work of bond dissociation. We report that a highly constrained residual compressive stress state, such as in an indent, leads to a work deficit in comparison to tension, which accounts for the slower dissolution rate of compressed bioactive glass. Such a mechanochemical effect suggests that the presence of residual stresses from the manufacture of biomedical implants and devices could lead to accelerated or delayed dissolution and that careful control of residual stresses should be sought for predictable performance in dissolvable materials.

Formulation and Evaluation of Mucoadhesive Floating Microspheres of Repaglinide

2021 ◽  
pp. 5673-5679
Author(s):  
S. Sivaprasad ◽  
V. Alagarsamy ◽  
M. Prathibha Bharathi ◽  
P.V. Murali Krishna ◽  
K. Sandeeep Kanna
Keyword(s):  
Controlled Release ◽  
Release Kinetics ◽  
In Vitro Release ◽  
Extended Period ◽  
Entrapment Efficiency ◽  
Sustain Release ◽  
S 100 ◽  
Eudragit S 100 ◽  
Good Flow

The main objective of the present study was to design a controlled release dosage form for an oral anti diabetic drug i.e. repaglinide employing polymers like eudragit s- 100. One of the other objective of this present study was to increase the biological half-life the drug by formulating into microspheres. The microspheres of repaglinide were prepared by solvent evaporation method by using eudragit s-100 and ethyl cellulose as polymers with different concentrations. Formulations (F1-F10) were prepared and evaluated for various micrometric properties and it was observed that though all the formulations were exhibited good flow properties, The F5 formulation exhibits higher in- vitro buoyancy time and entrapment efficiency which is considered for in- vitro and mucoadhesive studies. The FTIR results reveal that there was no interaction between the drug and the excipients. The in- vitro release profiles of F1-F5 indicated that all formulations showed controlled release over an extended period, with acceptable release kinetics. Among the all formulations F5 were considered as a promising candidate for sustain release of repaglinide.

Formulation and Evaluation of Luliconazole Microsponges Loaded Gel for Topical Delivery

2021 ◽  
pp. 5775-5780
Author(s):  
Farhana Sultan ◽  
Himansu Chopra ◽  
Gyanendra Kumar Sharma
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Ethyl Cellulose ◽  
Entrapment Efficiency ◽  
Topical Delivery ◽  
Production Yield ◽  
In Vitro Drug Release ◽  
Eudragit Rs ◽  
Diffusion Studies

Microsponge containing Luliconazole (LCZ) with different proportion of drug:polymer (Ethyl cellulose and Eudragit RS 100) were obtained efficiently using Quasi-emulsion solvent diffusion method. Luliconazole is an anti-fungal drug used for the topical delivery. The purpose of the microsponge formulation is to control the release of LCZ drug to the skin through Microsponge Delivery System (MDS) known to be the novel technique which overcome the maximum concentration of active ingredient, frequency doses, and skin irritation. The prepared microsponges were examined using drug content, % production yield, % entrapment efficiency and in-vitro drug release. The formulation were subjected to in-vitro drug release studies for 6 hr in which it was concluded that Ethyl cellulose microsponges formulated by drug:polymer (1:1) and Eudragit RS 100 microsponges formulated by drug:polymer (1:3) showed maximum controlled release i.e., Increase in drug:polymer ratio (1:1 to 1:9) increased the production yield and entrapment efficiency of microsponges using Ethyl cellulose with no significant effect for Eudragit RS 100.Therefore, both formulation F1 and F2 was dispersed in carbopol gel preparation for controlled delivery of LCZ to the skin. Various physical parameters like pH, spreadability, viscosity and in-vitro drug diffusion studies were evaluated for the prepared gel formulations. Microsponge gel formulation i.e., FG1 showed better results for controlled release of 89.40% as compared to FG2 i.e., 92.18% over the period of 12 hrs which is performed in Franz Diffusion Cell. On basis of in-vitro diffusion studies for LCZ gel formulation, microsponges using Ethyl cellulose (FG1) was found to be best for its controlled release of LCZ for 12 hrs and followed zero order kinetics. Hence, formulated LCZ loaded gel have potential to treat fungal infections i.e., tinea pedis, tinea cruris and tinea corporis.

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