Degradation Control of Collagen by Epigallocatechin-3-O-Gallate

2007 ◽  
Vol 342-343 ◽  
pp. 781-784 ◽  
Author(s):  
Han Hee Cho ◽  
Kazuaki Matsumura ◽  
Naoki Nakajima ◽  
Dong Wook Han ◽  
Sadami Tsutsumi ◽  
...  
Keyword(s):  
Biomedical Applications ◽  
Enzymatic Degradation ◽  
Egcg Treatment ◽  
Fibrous Protein ◽  
Gel Fraction ◽  
Tissue Culture Plate ◽  
Enzymatic Degradability ◽  
The Stability ◽  
Proliferation Assays

Stabilization of the fibrous protein collagen is important in biomedical applications. This study investigated the efficacy of degradation control of collagen using (-)-epigallocatechin-3-Ogallate (EGCG). EGCG treatment of collagen in solid state was carried out and collagen sponges produced were characterized by measuring the physicochemical properties such as gel fraction, the enzymatic degradability and cytocompatibility. According to gel fraction, EGCG-treated sponges showed the increase of insolubility compared to intact sponges. It showed that EGCG played a role in a crosslinker of collagen. Through in vitro enzymatic degradation test, EGCG-treated collagen sponges showed significant enhancement of resistance to collagenase in comparison with 25 mM EDC-treated collagen sponges. Also, cell proliferation assays showed that 40 mM EGCG-treated collagen sponges exhibited similar cytocompatibility properties compared with tissue culture plate. In summary, EGCG treatment of collagen sponges increased the stability of collagen. Therefore, crosslinking of collagen based scaffold with EGCG imparted more desirable properties, making it more applicable for use as a scaffold in tissue engineering applications.

3D Printed PLA/PCL/TiO2 Composite for Bone Replacement and Grafting

MRS Advances ◽  
2018 ◽  
Vol 3 (40) ◽  
pp. 2373-2378 ◽  
Author(s):  
Sandra E. Nájera ◽  
Monica Michel ◽  
Nam-Soo Kim
Keyword(s):  
Biomedical Applications ◽  
Fused Deposition Modeling ◽  
Fracture Strain ◽  
Fused Deposition ◽  
In Vitro Biocompatibility ◽  
Bone Replacement ◽  
Deposition Modeling ◽  
3D Printed ◽  
The Stability

ABSTRACTPolymer composites of Polylactic acid (PLA) and poly-ε-caprolactone (PCL), containing small amounts of titanium oxide (TiO2) were developed for biomedical applications. These composite materials were prepared, and then printed using Fused Deposition Modeling (FDM). 3D printed structures were characterized to determine their mechanical properties and biocompatibility. DSC analysis yielded useful information regarding the immiscibility of the different polymers, and it was observed that the particles of TiO2 improved the stability of the polymers. The ultimate tensile strength and the fracture strain increased by adding TiO2 as a filler, resulting in values of approximately 45 MPa and 5.5 % elongation. The printed composites show excellent in vitro biocompatibility including cell proliferation and adhesion, and are therefore promising candidates to be used in the biomedical field for bone replacement procedures, due to their properties similar to those of cancellous bone.

Photo-Crosslinkable Double-Network Hyaluronic Acid Based Hydrogel Dressing

2020 ◽  
Vol 982 ◽  
pp. 59-66
Author(s):  
Yu Long Ding ◽  
Hong Bo Zhang ◽  
Rui Xue Yin ◽  
Wen Jun Zhang
Keyword(s):  
Hyaluronic Acid ◽  
Biomedical Applications ◽  
Degradation Rate ◽  
In Vitro Degradation ◽  
Double Network ◽  
Biological Potential ◽  
Human Dermis ◽  
Enzymatic Degradability ◽  
Hdf Cells

Hyaluronic acid (HA)-based hydrogels are widely used in biomedical applications due to their excellent biocompatibility and enzymatic degradability. In this paper a photo-crosslinking double-network hyaluronic acid-based hydrogel dressing was proposed. Hyaluronic acid can be UV-crosslinked by modification with methacrylic anhydride (HA-MA) and disulfide-crosslinked by modification with 3,3'-dithiobis (propionylhydrazide) (DTP) (HA-SH). The mixings of these two materials at different ratios were produced. All the samples can be quickly gelled at 365 nm for 10 s. The rheological tests show that the storage modulus (G') of the double network (HA-SH/HA-MA) hydrogel is increased with the increase of HA-SH content. The HA-SH/HA-MA hydrogel has porous structure, high swelling ratio and Controlled degradation rate. In vitro degradation tests show that the ratio of HA-SH/HA-MA ratio was 9:1 (S9M1) in 100 U/ml hyaluronidase (Hase) degraded by 89.91±2.26% at 11d. The cytocompatibility of HA-SH/HA-MA hydrogels was proved by Live/Dead stainings and CCK-8 assays in the human dermis fibroblasts (HDF) cells test. All these results highlight the biological potential of the HA-SH/HA-MA hydrogels for DFU intervention.

scholarly journals Genipin Cross-Linked Polymeric Alginate-Chitosan Microcapsules for Oral Delivery: In-Vitro Analysis

2009 ◽  
Vol 2009 ◽  
pp. 1-16 ◽  
Author(s):  
Hongmei Chen ◽  
Wei Ouyang ◽  
Christopher Martoni ◽  
Satya Prakash
Keyword(s):  
Oral Delivery ◽  
Biomedical Applications ◽  
Enzymatic Degradation ◽  
Delivery Vehicle ◽  
Shear Forces ◽  
Chitosan Membrane ◽  
Molecular Weight Cutoff ◽  
Vitro Analysis ◽  
In Vitro Analysis

We have previously reported the preparation of the genipin cross-linked alginate-chitosan (GCAC) microcapsules composed of an alginate core with a genipin cross-linked chitosan membrane. This paper is the further investigation on their structural and physical characteristics. Results showed that the GCAC microcapsules had a smooth and dense surface and a networked interior. Cross-linking by genipin substantially reduced swelling and physical disintegration of microcapsules induced by nongelling ions and calcium sequestrants. Strong resistance to mechanical shear forces and enzymatic degradation was observed. Furthermore, the GCAC membranes were permeable to bovine serum albumin and maintained a molecular weight cutoff at 70 KD, analogous to the widely studied alginate-chitosan, and alginate-poly-L-lysine-alginate microcapsules. The release features and the tolerance of the GCAC microcapsules in the stimulated gastrointestinal environment were also investigated. This GCAC microcapsule formulation offers significant potential as a delivery vehicle for many biomedical applications.

scholarly journals In Vitro Cell Responses of MG-63 Osteoblast Cells on Bioactive Diopside and Wollastonite Nano-Bioceramics for Biomedical Applications

2020 ◽  
Author(s):  
Ruhollah Zamani Foroushani ◽  
Ebrahim Karamian ◽  
Mohammad Rafienia
Keyword(s):  
Cell Proliferation ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Biomedical Applications ◽  
Silicate Network ◽  
Osteoblast Cells ◽  
Alizarin Red ◽  
Cell Responses ◽  
The Stability

Abstract The present study aimed to synthesize and characterize diopside (CaMgSi2O6) and wollastonite (CaSiO3) nano-bioceramics via a combination of mechano-chemical and calcination processes. In vitro biomineralization and cell responses of wollastonite and diopside were performed on simulated body fluid (SBF) and MG-63 osteoblast cells. Results revealed proper tissue biomineralization of wollastonite and diopside through the generation of an apatite-like layer on the surface of nano-bioceramics. Cell responses of wollastonite and diopside eventuated non-cytotoxicity by MG-63 osteoblast cells, and their viability and cell proliferation were confirmed. Alizarin red staining of diopside and wollastonite evidenced great bioactivity and tissue biomineralization, and the ALP enzyme of diopside and wollastonite was enhanced in contact with the MG-63 osteoblast cells. Regarding the existence of Mg2+ in the calcium-silicate network and the stability network, diopside illustrated high biological and cell responses in comparison to wollastonite, and both of them were suggested as bioactive and biocompatible nano-bioceramics for biomedical applications.

scholarly journals Green Synthesis of Gold Nanoparticles Capped with Procyanidins from Leucosidea sericea as Potential Antidiabetic and Antioxidant Agents

Biomolecules ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 452 ◽  
Author(s):  
Umar M. Badeggi ◽  
Enas Ismail ◽  
Adewale O. Adeloye ◽  
Subelia Botha ◽  
Jelili A. Badmus ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Biomedical Applications ◽  
Chemical Constituents ◽  
Total Extract ◽  
Au Nps ◽  
Antioxidant Agents ◽  
The Stability ◽  
In Vitro Stability ◽  
Alpha Glucosidase

In this study, procyanidins fractions of dimers and trimers (F1–F2) from the Leucosidea sericea total extract (LSTE) were investigated for their chemical constituents. The total extract and the procyanidins were employed in the synthesis of gold nanoparticles (Au NPs) and fully characterized. Au NPs of 6, 24 and 21 nm were obtained using LSTE, F1 and F2 respectively. Zeta potential and in vitro stability studies confirmed the stability of the particles. The enzymatic activity of LSTE, F1, F2 and their corresponding Au NPs showed strong inhibitory alpha-amylase activity where F1 Au NPs demonstrated the highest with IC50 of 1.88 µg/mL. On the other hand, F2 Au NPs displayed the strongest alpha-glucosidase activity at 4.5 µg/mL. F2 and F2 Au NPs also demonstrated the highest antioxidant activity, 1834.0 ± 4.7 μM AAE/g and 1521.9 ± 3.0 μM TE/g respectively. The study revealed not only the ability of procyanidins dimers (F1 and F2) in forming biostable and bioactive Au NPs but also, a significant enhancement of the natural products activities, which could improve the smart delivery in future biomedical applications.

Formation and Structure of Casein Micelles in Lactating Mammary Tissue

1970 ◽  
Vol 28 ◽  
pp. 150-151
Author(s):  
Robert J. Carroll ◽  
Marvin P. Thompson ◽  
Harold M. Farrell
Keyword(s):  
Size Distribution ◽  
G Protein ◽  
Milk Proteins ◽  
Mammary Tissue ◽  
Colloidal System ◽  
Casein Micelles ◽  
The Stability

Milk is an unusually stable colloidal system; the stability of this system is due primarily to the formation of micelles by the major milk proteins, the caseins. Numerous models for the structure of casein micelles have been proposed; these models have been formulated on the basis of in vitro studies. Synthetic casein micelles (i.e., those formed by mixing the purified αsl- and k-caseins with Ca2+ in appropriate ratios) are dissimilar to those from freshly-drawn milks in (i) size distribution, (ii) ratio of Ca/P, and (iii) solvation (g. water/g. protein). Evidently, in vivo organization of the caseins into the micellar form occurs in-a manner which is not identical to the in vitro mode of formation.

Biological and biomedical applications of collagenous biomaterials

1990 ◽  
Vol 48 (3) ◽  
pp. 856-857
Author(s):  
Yasushi P. Kato ◽  
Michael G. Dunn ◽  
Frederick H. Silver ◽  
Arthur J. Wasserman
Keyword(s):  
Biomedical Applications ◽  
Soft Tissues ◽  
Collagen Fibers ◽  
Bone Collagen ◽  
Cover Slip ◽  
Fibroblast Migration ◽  
Cellular Expression ◽  
Defect Repair

Collagenous biomaterials have been used for growing cells in vitro as well as for augmentation and replacement of hard and soft tissues. The substratum used for culturing cells is implicated in the modulation of phenotypic cellular expression, cellular orientation and adhesion. Collagen may have a strong influence on these cellular parameters when used as a substrate in vitro. Clinically, collagen has many applications to wound healing including, skin and bone substitution, tendon, ligament, and nerve replacement. In this report we demonstrate two uses of collagen. First as a fiber to support fibroblast growth in vitro, and second as a demineralized bone/collagen sponge for radial bone defect repair in vivo.For the in vitro study, collagen fibers were prepared as described previously. Primary rat tendon fibroblasts (1° RTF) were isolated and cultured for 5 days on 1 X 15 mm sterile cover slips. Six to seven collagen fibers, were glued parallel to each other onto a circular cover slip (D=18mm) and the 1 X 15mm cover slip populated with 1° RTF was placed at the center perpendicular to the collagen fibers. Fibroblast migration from the 1 x 15mm cover slip onto and along the collagen fibers was measured daily using a phase contrast microscope (Olympus CK-2) with a calibrated eyepiece. Migratory rates for fibroblasts were determined from 36 fibers over 4 days.

Kinetics of Various 99mTc-Sn-Pyrophosphate Compounds in the Rat

1977 ◽  
Vol 16 (04) ◽  
pp. 157-162 ◽  
Author(s):  
C. Schümichen ◽  
B. Mackenbrock ◽  
G. Hoffmann
Keyword(s):  
Normal Saline ◽  
Half Life ◽  
Compound A ◽  
Short Half Life ◽  
Low Concentrations ◽  
The Stability ◽  
Kinetics Of ◽  
In Vitro Stability

SummaryThe bone-seeking 99mTc-Sn-pyrophosphate compound (compound A) was diluted both in vitro and in vivo and proved to be unstable both in vitro and in vivo. However, stability was much better in vivo than in vitro and thus the in vitro stability of compound A after dilution in various mediums could be followed up by a consecutive evaluation of the in vivo distribution in the rat. After dilution in neutral normal saline compound A is metastable and after a short half-life it is transformed into the other 99mTc-Sn-pyrophosphate compound A is metastable and after a short half-life in bone but in the kidneys. After dilution in normal saline of low pH and in buffering solutions the stability of compound A is increased. In human plasma compound A is relatively stable but not in plasma water. When compound B is formed in a buffering solution, uptake in the kidneys and excretion in urine is lowered and blood concentration increased.It is assumed that the association of protons to compound A will increase its stability at low concentrations while that to compound B will lead to a strong protein bond in plasma. It is concluded that compound A will not be stable in vivo because of a lack of stability in the extravascular space, and that the protein bond in plasma will be a measure of its in vivo stability.

Reverse torque values of abutment screws after dynamic loading: The effects of sealant agents and the taper of conical connections

2020 ◽  
Author(s):  
Arda Ozdiler ◽  
suleyman dayan ◽  
Burc Gencel ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Dynamic Loading ◽  
Antibacterial Agent ◽  
In Vitro Study ◽  
Control Group ◽  
Silicone Sealant ◽  
Reverse Torque ◽  
The Stability ◽  
Torque Values ◽  
Chlorhexidine Gel

This in vitro study evaluated the influence of taper angles on the internal conical connections of implant systems and of the application of chlorhexidine gel as an antibacterial agent or a polyvinyl siloxane (PVS) sealant on the reverse torque values of abutment screws after dynamic loading. The current study tested four implant systems with different taper angles (5.4°, 12°, 45°, and 60°). Specimens were divided into three groups: control (neither chlorhexidine gel filled nor silicone sealed), 2% chlorhexidine gel-filled or silicone-sealed group, and group subjected to a dynamic load of 50 N at 1 Hz for 500,000 cycles prior to reverse torque measurements. Quantitative positive correlation was observed between the taper angle degree and the percentage of tightening torque loss. However, this correlation was significant only for the 60° connection groups except in the group in which a sealant was applied ( p = 0.013 for the control group, p = 0.007 for the chlorhexidine group). Percentages of decrease in the torque values of the specimens with silicone sealant application were significantly higher compared with both the control and chlorhexidine groups ( p = 0.001, p = 0.002, p = 0.001, and p = 0.002, respectively, according to the increasing taper angles); the percentage of decrease in torque values due to chlorhexidine application was statistically insignificant when compared with the control group. The application of gel-form chlorhexidine as an antibacterial agent does not significantly affect the stability of the implant–abutment connection under dynamic loads. PVS sealants may cause screw loosening under functional loads.

Using FRET to Measure the Time it Takes for a Cell to Destroy a Virus

2019 ◽  
Author(s):  
Candace E. Benjamin ◽  
Zhuo Chen ◽  
Olivia Brohlin ◽  
Hamilton Lee ◽  
Stefanie Boyd ◽  
...  
Keyword(s):  
Cellular Uptake ◽  
Rhodamine B ◽  
Virus Like Particle ◽  
A Cell ◽  
Viral Nanoparticles ◽  
The Stability ◽  
Open Question ◽  
Viral Surface ◽  
Fret Pair

<div><div><div><p>The emergence of viral nanotechnology over the preceding two decades has created a number of intellectually captivating possible translational applications; however, the in vitro fate of the viral nanoparticles in cells remains an open question. Herein, we investigate the stability and lifetime of virus-like particle (VLP) Qβ - a representative and popular VLP for several applications - following cellular uptake. By exploiting the available functional handles on the viral surface, we have orthogonally installed the known FRET pair, FITC and Rhodamine B, to gain insight of the particle’s behavior in vitro. Based on these data, we believe VLPs undergo aggregation in addition to the anticipated proteolysis within a few hours of cellular uptake.</p></div></div></div>

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