Temperature-sensitive chitosan-poly(N-isopropylacrylamide) interpenetrated networks with enhanced loading capacity and controlled release properties

Alvarez‐Lorenzo, Carmen; Dubovik, Alexander S.; Grinberg, Natalia V.; Burova, Tatiana V.; Grinberg, V. Ya.

doi:10.1016/j.jconrel.2004.10.021

Cited by 181 publications

(78 citation statements)

References 31 publications

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“…However, all hydrogels tested showed a temperature for the phase transition close to that of the pure PNIPAAm hydrogel. It is reasonable to believe that the intrinsic properties of PNIPAAm subchains in CPN, in particular the transition free energy, are very close to those of the reference hydrogel (Alvarez-Lorenzo et al 2005).…”

Section: The Delivery Of Platinum Drugs From Thermosensitive Hydrogelmentioning

confidence: 82%

The Delivery of Platinum Drugs from Thermosensitive Hydrogels Containing Different Ratios of Chitosan

et al. 2008

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New thermosensitive hydrogels of poly(N-isopropylacrylamide) (PNIPAAm) with chitosan (CPN) were prepared and evaluated for use in the delivery of the platinum drugs, cisplatin and carboplatin. The effects of polymers containing different ratios of chitosan on the physicochemical and drug release characteristics were examined. The sol-gel transition temperature of the hydrogels was determined by differential scanning calorimetry (DSC) and viscometry. Discrepancies in the transition temperature among the various polymer systems were more pronounced when determined by viscosity compared by DSC, with the CPN showing a higher transition temperature than PNIPAAm. The cross-sectional structure and surface topography of the hydrogels were examined by scanning electronic microscopy (SEM) and atomic force microscopy (AFM), respectively. The incorporation of chitosan further increased the entanglement of the hydrogel network. An increase in the chitosan ratio in the polymers (CPN-H) also increased the cross-linking structure. A smoother surface of hydrogel matrices was observed for CPN compared with PNIPAAm. All hydrogels tested significantly reduced drug release compared with an aqueous solution. The release rate of platinum drugs from PNIPAAm was retarded at the late stage. CPN matrices could continuously deliver platinum drugs during the experiment. The rate of release from CPN-H was generally slower than that from hydrogels and had a lower chitosan ratio (CPN-L), presumably due to the more-tortuous pathways in the hydrogels. Thermosensitive hydrogels like those prepared in

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Section: The Delivery Of Platinum Drugs From Thermosensitive Hydrogelmentioning

confidence: 82%

The Delivery of Platinum Drugs from Thermosensitive Hydrogels Containing Different Ratios of Chitosan

et al. 2008

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“…This property is not found in native xyloglucan [220]. Further, Grinberg et al developed temperature-sensitive chitosan-poly(NIPAM) based interpenetrating networks (IPNs) with enhanced drug loading capacity and exhibiting controlled drug release kinetics [221]. The IPNs were formed by free-radical polymerization using bisacrylamide as crosslinker, followed by subsequent crosslinking of chitosan with glutaraldehyde solutions, to form fully interpenetrated networks.…”

Section: Temperature-sensitive or Thermo-responsive Gelsmentioning

confidence: 99%

Smart polymeric gels: Redefining the limits of biomedical devices

Chaterji

Kwon

Park

2007

Progress in Polymer Science

559

364

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This review describes recent progresses in the development and applications of smart polymeric gels, especially in the context of biomedical devices. The review has been organized into three separate sections: defining the basis of smart properties in polymeric gels; describing representative stimuli to which these gels respond; and illustrating a sample application area, namely, microfluidics. One of the major limitations in the use of hydrogels in stimuli-responsive applications is the diffusion rate limited transduction of signals. This can be obviated by engineering interconnected pores in the polymer structure to form capillary networks in the matrix and by downscaling the size of hydrogels to significantly decrease diffusion paths. Reducing the lag time in the induction of smart responses can be highly useful in biomedical devices, such as sensors and actuators. This review also describes molecular imprinting techniques to fabricate hydrogels for specific molecular recognition of target analytes. Additionally, it describes the significant advances in bottom-up nanofabrication strategies, involving supramolecular chemistry. Learning to assemble supramolecular structures from nature has led to the rapid prototyping of functional supramolecular devices. In essence, the barriers in the current performance potential of biomedical devices can be lowered or removed by the rapid convergence of interdisciplinary technologies.

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“…Also, pH-responsive, freeze-dried chitosan-polyvinyl pyrrolidone (PVP) hydrogels [50] and chitosan-PVA hydrogels [51] were developed for drug delivery applications by cross-linking with glutaraldehyde. The potential of post cross-linking of chitosan, after preparing a semiinterpenetrating polymer network (semi-IPN) with PNIPAAm to create temperature-responsive and pHsensitive IPNs for drug delivery, has also been studied [44]. Further, CMC [52] and N-(2-carboxybenzyl)-chitosan hydrogels [53] have been prepared by reacting glutaraldehyde with the respective chitosan derivative.…”

Section: Glutaraldehydementioning

confidence: 99%

“…Thus, in the current chapter, an overview on the drug delivery applications of cross-linked [23] and chemically modified chitosan is given. Important modified and cross-linked derivatives include carboxymethyl-chitosan (CMC), O-carboxymethyl-chitosan (O-CMC), N,O-carboxymethyl-chitosan (N,O-CMC) and N-carboxymethyl-chitosan (N-CMC) [14][15][16][17][18][19], succinylchitosan [24][25][26][27][28][29][30][31][32], thiolated chitosan [33][34][35][36][37][38][39][40][41][42][43], and chitosan grafted with PNIPAAm and PNVCL (chitosang-PNIPAAm and chitosan-g-PNVCL) [44][45][46][47].…”

Section: Introductionmentioning

confidence: 99%