scholarly journals Biological Compatibility of a Polylactic Acid Composite Reinforced with Natural Chitosan Obtained from Shrimp Waste

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1465 ◽  
Author(s):  
Yaret Torres-Hernández ◽  
Gloria Ortega-Díaz ◽  
Lucía Téllez-Jurado ◽  
Nayeli Castrejón-Jiménez ◽  
Alejandro Altamirano-Torres ◽  
...  
Keyword(s):  
Cell Viability ◽  
Polylactic Acid ◽  
Low Cost ◽  
Hydrolytic Degradation ◽  
Phosphate Buffer Solution ◽  
Morphological Characteristics ◽  
Buffer Solution ◽  
Composite Surface ◽  
Biological Compatibility

The aim of this work is to evaluate the effect of chitosan content (1, 3 and 5 wt %) dispersed in polylactic acid (PLA) on the structure and properties of composites. Also, the hydrolytic degradation, and the cell viability and adhesion of human MG-63 osteoblasts are analyzed to determine the composites’ suitability for use in tissue engineering. For the manufacture of the materials, natural chitosan was extracted chemically from shrimp exoskeleton. The composites were fabricated by extrusion, because it is a low-cost process, it is reproducible, and it does not compromise the biocompatibility of the materials. FT-IR and XRD show that the chitosan does not change the polymer structure, and interactions between the composite components are discarded. In vitro degradation tests show that the composites do not induce significant pH changes in phosphate buffer solution due to their low susceptibility to hydrolytic degradation. The adhesion and morphological characteristics of the osteoblasts are evaluated using confocal microscopy and scanning electron microscopy. The cell viability is determined by the MTT assay. Osteoblasts adhesion is observed on the surface of PLA and composites. A higher amount of chitosan, higher number of cells with osteoblastic morphology, and mineralized nodules are observed on the composite surface. The highest metabolic activity is evidenced at 21 days. The results suggest that the Polylactic acid/chitosan composites are potentially suitable for use as a biomaterial.

scholarly journals In Vitro Biodegradation Pattern of Collagen Matrices for Soft Tissue Augmentation

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2633
Author(s):  
Cristina Vallecillo ◽  
Manuel Toledano-Osorio ◽  
Marta Vallecillo-Rivas ◽  
Manuel Toledano ◽  
Raquel Osorio
Keyword(s):  
Soft Tissue ◽  
Hydrolytic Degradation ◽  
Phosphate Buffer Solution ◽  
Soft Tissue Augmentation ◽  
Buffer Solution ◽  
Collagen Matrices ◽  
Bacterial Collagenase ◽  
Tissue Augmentation ◽  
Tissue Grafts

Collagen matrices have become a great alternative to the use of connective tissue grafts for soft tissue augmentation procedures. One of the main problems with these matrices is their volume instability and rapid degradation. This study has been designed with the objective of examining the degradation of three matrices over time. For this purpose, pieces of 10 × 10 mm2 of Fibro-Gide, Mucograft and Mucoderm were submitted to three different degradation tests—(1) hydrolytic degradation in phosphate buffer solution (PBS); (2) enzyme resistance, using a 0.25% porcine trypsin solution; and (3) bacterial collagenase resistance (Clostridium histolyticum)—over different immersion periods of up to 50 days. Weight measurements were performed with an analytic microbalance. Thickness was measured with a digital caliper. A stereomicroscope was used to obtain the matrices’ images. ANOVA and Student–Newman–Keuls tests were used for mean comparisons (p < 0.05), except when analyzing differences between time-points within the same matrix and solution, where pair-wise comparisons were applied (p < 0.001). Fibro-Gide attained the highest resistance to all degradation challenges. The bacterial collagenase solution was shown to constitute the most aggressive test as all matrices presented 100% degradation before 14 days of storage.

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.

Non-enzymatic determination of purine nucleotides using a carbon dot modified glassy carbon electrode

2019 ◽  
Vol 11 (30) ◽  
pp. 3866-3873 ◽  
Author(s):  
R. Karthikeyan ◽  
D. James Nelson ◽  
S. Abraham John
Keyword(s):  
Glassy Carbon ◽  
Low Cost ◽  
Phosphate Buffer Solution ◽  
Purine Nucleotides ◽  
Buffer Solution ◽  
Solution Ph ◽  
Carbon Dot ◽  
Enzymatic Determination ◽  
Sensitive Determination

Selective and sensitive determination of one of the purine nucleotides, inosine (INO) using a low cost carbon dot (CD) modified glassy carbon (GC) electrode in 0.2 M phosphate buffer solution (pH 7.2) was demonstrated in this paper.

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.

The Study of Albumin Release from Silica/Albumin as a Potential Drug Delivery Carrier

2014 ◽  
Vol 69 (5) ◽  
Author(s):  
Shafiyah Pondi ◽  
Jon Efendi ◽  
Ho Chin Siong ◽  
Lai Sin Yuan ◽  
Sheela Chandren ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Fumed Silica ◽  
In Vitro Release ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Solution Ph ◽  
Drug Delivery Carrier ◽  
High Interaction ◽  
Uv Visible

The drug-delivery field has been an attractive as well as challenging area for research. With the emerging of new formulated drugs and pharmaceutical compounds, development of good drug-delivery system (DDS) is crucially required. This study aims to utilize albumin as the drug template in silica/albumin/drug (S/A/D) system. Prior to designing this system, the interaction between silica and albumin was investigated. It is hypothesized that high interaction between silica and albumin may result in slower drug release over time, which is preferred for a good DDS. Silica and albumin (S/A) materials were prepared by using fumed silica and tetraethyl orthosilicate (TEOS) as the silica precursors. Three different S/A samples were prepared; fumed silica with albumin (FS/A), fumed silica with pre-treated albumin by sodium borohydrate (FS/A-N), and silica sol (TEOS) with albumin (SS/A). In-vitro release of albumin in phosphate buffer solution (pH 7) was carried out to examine the interaction between albumin and silica. The concentration of albumin was detected at 280 nm by UV-visible spectrophotometer. All samples were characterized by diffuse reflectance-UV-visible spectrophotometer (DR-UV), Fourier transform infrared spectrophotometer (FTIR) dan thermogravimetric-differential thermal analysis (TG-DTA). DR-UV results show that SS/A exhibited the lowest absorption intensity at 280 nm, which indicates better interaction between silica and albumin. This result was supported by the presence of Si-O stretching band of silanol at 952 cm-1 from the FTIR spectrum. Release study of albumin demonstrated that the release of albumin from SS/A was slowest compared to those of FS/A and FS/A-N. 

Drug-loaded ultrafine poly(vinyl alcohol) fibre mats prepared by electrospinning

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Chunxue Zhang ◽  
Xiaoyan Yuan ◽  
Lili Wu ◽  
Jing Sheng
Keyword(s):  
Drug Release ◽  
Photoelectron Spectroscopy ◽  
Vinyl Alcohol ◽  
Phosphate Buffer Solution ◽  
Poly Vinyl Alcohol ◽  
High Porosity ◽  
Buffer Solution ◽  
Drug Molecules ◽  
Alcohol Fibre

AbstractSubmicron poly(vinyl alcohol) (PVA) fibre mats embedded with Aspirin and bovine serum albumin (BSA) were prepared by electrospinning of their aqueous solutions. Fibre morphology was investigated by scanning electron microscopy. The composition of the fibre mats was characterized by Fourier transform IR spectroscopy and X-ray photoelectron spectroscopy. The in vitro drug release was investigated by immersing the fibre mats in phosphate buffer solution at 37°C. Results indicated that the morphology of fibre mats was influenced by the amount of drug, and more beaded and irregularly shaped fibres were found with increasing drug amounts. There were drug molecules distributed on the surface of the PVA fibres. Studies of in vitro drug release showed that both Aspirin and BSA were released more quickly from PVA fibre mats than from PVA films because of the large surface area and high porosity of the fibre mats.

scholarly journals Synthesis, Characterization, and Biodegradation Studies of Poly(1,4-cyclohexanedimethylene-adipate-carbonate)s

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Ajay S. Chandure ◽  
Ganesh S. Bhusari ◽  
Suresh S. Umare
Keyword(s):  
Weight Loss ◽  
Enzymatic Degradation ◽  
Hydrolytic Degradation ◽  
Phosphate Buffer Solution ◽  
Film Surface ◽  
Solution Viscosity ◽  
Buffer Solution ◽  
Sem Images ◽  
Titanium Butoxide ◽  
Soil Burial

Aliphatic/alicyclic poly(1,4-cyclohexanedimethylene-adipate-carbonate)s (PCACs) were synthesized by a transesterification from 1,4-cyclohexamethylendimethanol (1,4-CHDM), adipic acid (AA), diethyl carbonate (DEC), and titanium butoxide Ti(OBu)4 as a transesterification catalyst. The synthesized PCACs were characterized by the Fourier transform infrared (FTIR), X-ray diffraction analysis (XRD), solubility, solution viscosity, gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and scanning electron microscope (SEM) for their structural, physical, thermal, and morphological investigation. The structure of synthesized PCACs was confirmed by FTIR. All TGA curves of PCACs shows 10% weight loss above 270°C, and they reveal good thermal stability. Biodegradability of PCACs was investigated by hydrolytic degradation at (pH 7.2 and 11.5), enzymatic degradation using Rhizopus delemar lips at 37°C in phosphate buffer solution (PBS), and soil burial degradation at 30°C. The hydrolytic degradation shows the greater rate of weight loss in PBS at pH-11.5 than pH-7.2. The hydrolytic and soil burial degradation shows faster rate of weight loss as compared to enzymatic degradation. Biodegradation rate of PCACs follows the order: PCAC-20 > PCAC-40 > PCAC-60. SEM images show that degradation occurred all over the film surface, creating holes and cracks. These biodegradable PCACs may be able to replace conventional polymer in the fabrication of packaging film in near future.

scholarly journals Differential Biodegradation Kinetics of Collagen Membranes for Bone Regeneration

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1290
Author(s):  
Manuel Toledano ◽  
Samara Asady ◽  
Manuel Toledano-Osorio ◽  
Franklin García-Godoy ◽  
María-Angeles Serrera-Figallo ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Hydrolytic Degradation ◽  
Phosphate Buffer Solution ◽  
Buffer Solution ◽  
Barrier Membranes ◽  
Time Points ◽  
Equine Pericardium ◽  
Collagen Membranes ◽  
Kinetics Of ◽  
Digital Caliper

Native collagen-based membranes are used to guide bone regeneration; but due to their rapid biodegradation, this treatment is often unpredictable. The purpose of this study was to investigate the biodegradability of natural collagen membranes. Three non-cross-linked resorbable collagen barrier membranes were tested: Derma Fina (porcine dermis), Evolution Standard (equine pericardium) and Duo-Teck (equine lyophilized collagen felt). 10 × 10 mm2 pieces of membranes were submitted to three different degradation procedures: (1) hydrolytic degradation in phosphate buffer solution, (2) enzyme resistance, using a 0.25% porcine trypsin solution, and (3) bacterial (Clostridium histolyticum) collagenase resistance test. Weight measurements were performed with an analytic microbalance. Thickness was measured with a digital caliper. Membranes were analyzed at different time-points, up to 21 d of immersion. A stereomicroscope was used to obtain membranes’ images. ANOVA and Student Newman Keuls were used for mean comparisons (p < 0.05), except when analyzing differences between time-points within the same membrane and solution where pair-wise comparisons were applied (p < 0.001). Derma Fina attained the highest resistance to all degradation challenges. Duo-Teck was the most susceptible membrane to degradation, complete degradation occurred as soon as 8 h. The bacterial collagenase solution performed as the most aggressive test as all membranes presented 100% degradation before 21 d.

scholarly journals Drug Leaching Properties of Vancomycin Loaded Mesoporous Hydroxyapatite as Bone Substitutes

Processes ◽  
2019 ◽  
Vol 7 (11) ◽  
pp. 826 ◽  
Author(s):  
Jayasingh Anita Lett ◽  
Suresh Sagadevan ◽  
Joseph Joyce Prabhakar ◽  
Nor Aliya Hamizi ◽  
Irfan Anjum Badruddin ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Pore Size ◽  
In Vitro Release ◽  
Phosphate Buffer Solution ◽  
Bone Substitutes ◽  
Organic Modifiers ◽  
Buffer Solution ◽  
Modern Health Care ◽  
Impregnation Technique

Infections after bone reconstructive surgery become an authentic therapeutic and economic issue when it comes to a modern health care system. In general; infected bone defects are regarded as contraindications for bone grafting. Since the pathogens develop a biofilm on the inner surface of the bone; local delivery of antibiotics becomes more important. The present work focuses on the synthesis of Mesoporous Hydroxyapatite (MPHAP) loaded with drug Vancomycin (Van) and to investigate its loading and leaching ability in phosphate buffer solution (PBS), to be used for post-operative infections. The effect of pore size on MPHAP was analyzed using different fatty acids as organic modifiers. The impacts of various fatty acids chain length on the morphology and pore size were studied. A simple impregnation technique with optimized conditions ensured a high antibiotic loading (up to 0.476 + 0.0135 mg/mL), with a complete in vitro release obtained within 50 h.

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