In vitro and in vivo assessment of novel pH-sensitive interpenetrating polymer networks of a graft copolymer for gastro-protective delivery of ketoprofen

RSC Advances ◽  
2016 ◽  
Vol 6 (69) ◽  
pp. 64344-64356 ◽  
Author(s):  
Rashmi Boppana ◽  
Raghavendra V. Kulkarni ◽  
G. Krishna Mohan ◽  
Srinivas Mutalik ◽  
Tejraj M. Aminabhavi
Keyword(s):  
Side Effects ◽  
Drug Release ◽  
Graft Copolymer ◽  
Polymer Networks ◽  
Ph Sensitive ◽  
Interpenetrating Polymer Networks ◽  
In Vivo Assessment

Novel pH-sensitive IPN microbeads exhibited drug release in response to changing pH and reduced side effects of ketoprofenin vivo.

scholarly journals In Vitro and In Vivo Evaluation of pH-Sensitive Hydrogels of Carboxymethyl Chitosan for Intestinal Delivery of Theophylline

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Hemant Kumar Singh Yadav ◽  
H. G. Shivakumar
Keyword(s):  
Drug Release ◽  
Sustained Release ◽  
Extended Release ◽  
Carboxymethyl Chitosan ◽  
Ph Sensitive ◽  
Acidic Ph ◽  
Release Formulation ◽  
Nocturnal Asthma

Chitosan is a natural polymer which has limited solubility. Chitosan gets solubilized at acidic pH but is insoluble at basic pH. In the present study, carboxymethyl chitosan (CMC) was prepared which shows high swelling in basic pH and thus can delay the drug release and can act as matrix for extended release formulation. CMC was characterized by FTIR and NMR. pH-sensitive hydrogels of theophylline were formulated using CMC and carbopol 934. Hydrogels were evaluated for swelling, drug content in vitro drug release studies, and in vivo studies on rabbit. The swelling studies have shown little swelling in acidic pH 432% at the end of two hours and 1631% in basic pH at the end of 12 hours. The release profile of the formulation I containing CMC and carbopol in 1 : 1 ratio showed sustained release. In vivo studies showed that the release of theophylline from the prepared hydrogel formulation (Test) exhibit better prolonged action when compared to (standard) marketed sustained release formulation. The studies showed that the pH-sensitive hydrogel of CMC can be used for extended release of theophylline in intestine and can be highly useful in treating symptoms of nocturnal asthma.

In vitro and in vivo evaluation of pirfenidone loaded acrylamide grafted pullulan-poly(vinyl alcohol) interpenetrating polymer networks

2018 ◽  
Vol 202 ◽  
pp. 288-298 ◽  
Author(s):  
Saundray Raj Soni ◽  
Nimmy Kumari ◽  
Bibhas K. Bhunia ◽  
Biswatrish Sarkar ◽  
Biman B. Mandal ◽  
...  
Keyword(s):  
Vinyl Alcohol ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Poly Vinyl Alcohol ◽  
In Vivo Evaluation

Two Novel Freeze-Dried pH-Sensitive Cyclosporine A Nanoparticles: Preparation, in vitro Drug Release, and in vivo Absorption Enhancement Effects

2009 ◽  
Vol 5 (4) ◽  
pp. 449-456 ◽  
Author(s):  
Fang Zhi-gang ◽  
Pan Ping ◽  
Yang Zhi-qiang ◽  
Chen Ya-gen ◽  
Zhang Jian-kang ◽  
...  
Keyword(s):  
Drug Release ◽  
Cyclosporine A ◽  
Ph Sensitive ◽  
Absorption Enhancement ◽  
In Vitro Drug Release ◽  
Freeze Dried ◽  
In Vivo Absorption

scholarly journals Interpenetrating Hydrogel Networks Enhance Mechanical Stability, Rheological Properties, Release Behavior and Adhesiveness of Platelet-Rich Plasma

2020 ◽  
Vol 21 (4) ◽  
pp. 1399 ◽  
Author(s):  
Roberta Censi ◽  
Cristina Casadidio ◽  
Siyuan Deng ◽  
Maria Rosa Gigliobianco ◽  
Maria Giovanna Sabbieti ◽  
...  
Keyword(s):  
Growth Factors ◽  
Mechanical Stability ◽  
Platelet Rich Plasma ◽  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Cartilage Defects ◽  
Lytic Enzymes ◽  
Thermal Gelation

Platelet-rich plasma (PRP) has attracted much attention for the treatment of articular cartilage defects or wounds due to its intrinsic content of growth factors relevant for tissue repair. However, the short residence time of PRP in vivo, due to the action of lytic enzymes, its weak mechanical properties and the consequent short-term release of bioactive factors has restricted its application and efficacy. The present work aimed at designing new formulation strategies for PRP, based on the use of platelet concentrate (PC)-loaded hydrogels or interpenetrating polymer networks, directed at improving mechanical stability and sustaining the release of bioactive growth factors over a prolonged time-span. The interpenetrating hydrogels comprised two polymer networks interlaced on a molecular scale: (a) a first covalent network of thermosensitive and biodegradable vinyl sulfone bearing p(hydroxypropyl methacrylamide-lacate)-polyethylene glycol triblock copolymers, tandem cross-linked by thermal gelation and Michael addition when combined with thiolated hyaluronic acid, and (b) a second network composed of cross-linked fibrin. The PC-loaded hydrogels, instead, was formed only by network (a). All the designed and successfully synthesized formulations greatly increased the stability of PRP in vitro, leading to significant increase in degradation time and storage modulus of PRP gel. The resulting viscoelastic networks showed the ability to controllably release platelet derived growth factor and transforming growth factr β1, and to improve the tissue adhesiveness of PRP. The newly developed hydrogels show great potential for application in the field of wound healing, cartilage repair and beyond.

scholarly journals Perilipin Expression Reveals Adipogenic Potential of hADSCs inside Superporous Polymeric Cellular Delivery Systems

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Sorina Dinescu ◽  
Bianca Galateanu ◽  
Adriana Lungu ◽  
Eugen Radu ◽  
Sorin Nae ◽  
...  
Keyword(s):  
Polymer Networks ◽  
Interpenetrating Polymer Networks ◽  
Porous Scaffolds ◽  
Cellular Delivery ◽  
Stem Cell Delivery ◽  
Cell Scaffold ◽  
Scaffold Structure

Recent progress in tissue engineering and regenerative medicine envisages the use of cell-scaffold bioconstructs to best mimic the naturalin vivomicroenvironment. Our aim was not only to develop novel 3D porous scaffolds for regenerative applications by the association of gelatin (G), alginate (A), and polyacrylamide (PAA) major assets but also to evaluate theirin vitropotential to support human adipose-derived stem cells (hADSCs) adipogenesis. G-A-PAA biomatrix investigated in this work is an interesting substrate combining the advantages of the three individual constituents, namely, biodegradability of G, hydrophilicity of A and PAA, superior elasticity at compression with respect to the G-A and PAA controls, and the capacity to generate porous scaffolds. hADSCs inside these novel interpenetrating polymer networks (IPNs) were able to populate the entire scaffold structure and to display their characteristic spindle-likeshape as a consequence of a good interaction with G component of the matrices. Additionally, hADSCs proved to display the capacity to differentiate towards mature adipocytes, to accumulate lipids inside their cytoplasm, and to express perilipin late adipogenic marker inside novel IPNs described in this study. On long term, this newly designed biomatrix aims to represent a stem cell delivery system product dedicated for modern regenerative strategies.

scholarly journals A pH-Sensitive Polymeric Micellar System Based on Chitosan Derivative for Efficient Delivery of Paclitaxel

2021 ◽  
Vol 22 (13) ◽  
pp. 6659
Author(s):  
Yang Han ◽  
Jieyi Pan ◽  
Na Liang ◽  
Xianfeng Gong ◽  
Shaoping Sun
Keyword(s):  
Drug Release ◽  
In Vitro Cytotoxicity ◽  
Ph Sensitive ◽  
Ultrasonic Probe ◽  
In Vitro Drug Release ◽  
Modified Chitosan ◽  
Efficient Delivery ◽  
The Mean

In this study, an amphiphilic conjugate based on mPEG and cholesterol-modified chitosan with hydrazone bonds in the molecules (mPEG-CS-Hz-CH) was successfully synthesized. Using the polymer as the carrier, the paclitaxel (PTX)-loaded mPEG-CS-Hz-CH micelles were prepared by an ultrasonic probe method. The mean particle size and zeta potential of the optimized PTX-loaded micelles were 146 ± 4 nm and +21.7 ± 0.7 mV, respectively. An in vitro drug release study indicated that the PTX-loaded mPEG-CS-Hz-CH micelles were stable under normal physiological conditions (pH 7.4), whereas rapid drug release was observed in the simulated tumor intracellular microenvironment (pH 5.0). An in vitro cytotoxicity study demonstrated the non-toxicity of the polymer itself, and the PTX-loaded micelles exhibited superior cytotoxicity and significant selectivity on tumor cells. An in vivo antitumor efficacy study further confirmed that the PTX-loaded micelles could improve the therapeutic efficacy of PTX and reduce the side effects. All these results suggested that the mPEG-CS-Hz-CH micelles might be promising pH-sensitive nanocarriers for PTX delivery.

A Comparative Ex Vivo Study of Plasminogen Activators and Proteases for Fibrinolytic Activity and Side Effects in Rabbits

1977 ◽  
Vol 37 (01) ◽  
pp. 154-161 ◽  
Author(s):  
B. A Janik ◽  
S. E Papaioannou
Keyword(s):  
Side Effects ◽  
Effective Dose ◽  
Fibrinolytic Activity ◽  
Ex Vivo ◽  
Plasminogen Activators ◽  
Assay System ◽  
Coagulation Parameters ◽  
Ex Vivo Assay

SummaryUrokinase, streptokinase, Brinase, trypsin, and SN 687, a bacterial exoprotease, have been evaluated in an ex vivo assay system. These enzymes were injected into rabbits and the fibrinolytic activity as well as other coagulation parameters were measured by in vitro techniques. Dose-response correlations have been made using the euglobulin lysis time as a measure of fibrinolytic activity and the 50% effective dose has been determined for each enzyme. Loading doses, equal to four times the 50% effective dose, were administered to monitor potential toxicity revealing that Brinase, trypsin, and SN 687 were very toxic at this concentration.Having established the 50% effective dose for each enzyme, further testing was conducted where relevant fibrinolytic and coagulation parameters were measured for up to two days following a 50% effective dose bolus injection of each enzyme. Our results have demonstrated that urokinase and streptokinase are plasminogen activators specifically activating the rabbit fibrinolytic system while Brinase, trypsin and SN 687 increase the general proteolytic activity in vivo.The advantages of this ex vivo assay system for evaluating relative fibrinolytic potencies and side effects for plasminogen activators and fibrinolytic proteases have been discussed.

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