Weibull Modeling of Controlled Drug Release from Ag-PMA Nanosystems

Abstract

Traditional pharmacotherapy suffers from multiple drawbacks that hamper patient treatment such as antibiotic resistances or low drug selectivity and toxicity during systemic applications. Some functional hybrid nanomaterials are designed to handle the drug release process under remote-control. More attention has recently been paid to synthetic polyelectrolytes for their intrinsic properties which allow them to rearrange into compact structures, ideal to be used as drug carriers or probes influencing biochemical processes. The presence of Ag nanoparticles (NPs) in the Poly methyl acrylate (PMA) matrix leads to an enhancement of drug release efficiency, even using a low-power laser whose wavelength is far from the Ag Surface Plasmon Resonance (SPR) peak. Further, compared to the colloids, the nanofiber-based drug delivery system has shown shorter response time and more precise control over the release rate. The efficiency and timing of involved drug release mechanisms has been estimated by the Weibull distribution function, whose parameters indicate that the release mechanism of nanofibers obeys Fick’s first law while a non-Fickian character controlled by diffusion and relaxation of polymer chains occurs in the colloidal phase.

Preparation and Drug Release Profile of Chitosan–Siloxane Hybrid Capsules Coated with Hydroxyapatite

“…The release percentage of cytochrome C from ChG2 and ChG2 + HAp and the constants derived from the Weibull model are shown in Figure 9 and Table 1 . The b value derived from the fitting of Equation (3) to the drug release curve data can be used to determine the release mechanism [ 19 , 20 , 21 ]. The b value for ChG2 was less than that of ChG2 + HAp.…”

“…The amount of cytochrome C released from the capsules into the saline solution was measured using a spectrum scanning multimode reader at 528 nm. The release profile was fitted using the Weibull function [ 19 , 20 , 21 ] as shown in Equation (3). This model has been used in drug release and dissolution studies [ 20 ].…”

“…The release profile was fitted using the Weibull function [ 19 , 20 , 21 ] as shown in Equation (3). This model has been used in drug release and dissolution studies [ 20 ]. k corresponds to the maximum amount of released drug.…”

Acrylate and Methacrylate Polymers’ Applications: Second Life with Inexpensive and Sustainable Recycling Approaches

“…Polymethacrylate electrolytes are also used to prepare light stimuli responsive systems based on noble metal-polymer framework, due to their ability to act as capping agent towards metal clusters. Corsaro et al developed light responsive drug nanocarriers, based on PMA sodium salt and Ag nanoparticles (see Figure 7 a) by a green approach [ 85 , 86 ]. The noble metal nanoparticles were prepared by radiolysis process of water: the reactive species reduce the metal ion (Ag + ) to zero valent state (Ag), which are stabilized via interactions with carboxylic functional groups of PMA sodium salt and act as capping agent.…”

“…The drug release process ( Figure 7 c,d) under irradiation stimulus is allowed by a reorganization of the polymeric matrix due to a hydrogen bonding dissociation process, while the increase of the temperature (up to about 60 °C) induces the aggregation of hydrophobic moieties. This is followed by the expulsion of water molecules by the PMAA network succeeded by the breakdown of polymeric structure [ 85 ].…”