Article

Molecular imprinting within hydrogels

NSF Program on Therapeutic and Diagnostic Devices, Purdue University, West Lafayette, IN 47907, USA.
Advanced Drug Delivery Reviews (Impact Factor: 12.71). 02/2002; 54(1):149-61. DOI: 10.1016/S0169-409X(01)00246-0
Source: PubMed

ABSTRACT Hydrogels have been used primarily in the pharmaceutical field as carriers for delivery of various drugs, peptides and proteins. These systems have included stimuli-responsive gels that exhibit reversible swelling behavior and hence can show modulated release in response to external stimuli such as pH, temperature, ionic strength, electric field, or specific analyte concentration gradients. The focus of this article is to review molecular imprinting within hydrogels and discuss recent efforts on analyte-responsive intelligent gels, specifically suggesting the possibility of utilizing molecular imprinting strategies to impart analyte specificity and responsiveness within these systems. Molecular imprinting is an emerging field that produces precise chemical architecture that can bind analytes and differentiate between similar molecules with enantiomeric resolution. On the forefront of imprinting gel systems are intelligent, stimuli-sensitive imprinted gels that modify their swelling behavior and in turn modulate their analyte binding abilities. We discuss the challenges creating an imprinting effect in hydrogels and the possibilities of using molecularly imprinted mechanisms within controlled release gels.

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    • "Besides the concept shown in Figure 3, the concept of intelligent drug delivery which refers to the predictable release of a drug in response to specific stimuli, such as the presence of another molecule has been a well-established drug release way from MIP carrier. Some excellent reviews have been published on the investigation of various aspects of MIPs in drug delivery (Byrne et al., 2002; Hillberg et al., 2005; Kryscio & Peppas, 2009; Rangasamy & Parthiban, 2010; Wang & Von Recum, 2011; Lulinski, 2013). Apart from numerous research reports published on various concepts of MIP-based DDS, some important contributions in the form of book chapters have also been devoted on extensive introduction and applications of MIP-based intelligent drug delivery (Alvarez-Lorenzo & Concheiro, 2013a,b; Alvarez-Lorenzo et al., 2013c–d). "
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    ABSTRACT: This review is aimed to discuss the molecular imprinted polymer (MIP)-based drug delivery systems (DDS). Molecular imprinted polymers have proved to possess the potential and also as a suitable material in several areas over a long period of time. However, only recently it has been employed for pharmaceuticals and biomedical applications, particularly as drug delivery vehicles due to properties including selective recognition generated from imprinting the desired analyte, favorable in harsh experimental conditions, and feedback-controlled recognitive drug release. Hence, this review will discuss their synthesis, the reason they are selected as drug delivery vehicles and for their applications in several drug administration routes (i.e. transdermal, ocular and gastrointestinal or stimuli-reactive routes).
    Drug Delivery 09/2014; DOI:10.3109/10717544.2014.970297 · 2.20 Impact Factor
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    • "To explore the concept of drug delivery by contact lens, a number of researchers have conducted laboratory-based drug release studies from contact lenses, and these studies show that both conventional and silicone hydrogel contact lenses release ophthalmic drugs in a short period of a few hours [9] [10] [11]. Recently several contact lens systems have been developed to increase the drug release duration, including nanoparticle-laden lenses [12] [13] [14] [15] [16], biomimetic and imprinted contact lenses [17] [18] [19] [20] [21] [22], and contact lens with layered structure [23]. Also, Chauhan and coworkers recently developed a new approach of creating sustained release from silicone hydrogel contact lenses by incorporating biocompatible diffusion barriers through incorporation of vitamin E aggregates, and these vitamin E loaded lenses maintains proper oxygen permeability, ion permeability, and light refractive property to be used as extended wear contact lenses [9] [11] [24]. "
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    ABSTRACT: We combine laboratory-based timolol release studies and in vivo pharmacodynamics studies in beagle dogs to evaluate the efficacy of glaucoma therapy through extended wear contact lenses. Commercial contact lenses cannot provide extended delivery of ophthalmic drugs and so the studies here focused on increasing the release duration of timolol from ACUVUE TruEye contact lenses by incorporating vitamin E diffusion barriers. The efficacy of timolol delivered via extended wear contact lenses was then compared to eye drops in beagle dogs that suffer from spontaneous glaucoma. The lenses were either replaced every 24h or continuously worn for 4 days, and the pharmacodynamics effect of changes in the intraocular pressure (IOP) of timolol from the ACUVUE TruEye contact lenses can be significantly increased by incorporation of vitamin E. The in vivo studies showed that IOP reduction from baseline by pure contact lens on daily basis was comparable with that by eye drops but with only 20% of drug dose, which suggested higher drug bioavailability for contact lenses. In addition, by inclusion of vitamin E into the lenses, the IOP was reduced significantly during the 4-day treatment with continuous wear of lens.
    Journal of Controlled Release 06/2012; 162(1):152-8. DOI:10.1016/j.jconrel.2012.06.017 · 7.26 Impact Factor
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    • "Two important concerns in the preparation of molecularly imprinted polymers (MIPs) for DDS are that the template (i.e. the drug of interest) has to be stable under the polymerization conditions and that no toxic solvents should remain on the device. In the particular case of SCLs, the cross-linking density has to be compatible with the required flexibility of the material and thus the imprinted cavities should possess high affinity for the drug in order to compensate for their lower physical stability [24] [26] [27]. "
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