Dual and multi-stimuli responsive polymeric nanoparticles for programmed site-specific drug delivery

A review on electrospinning for membrane fabrication: Challenges and applications

Rapid and high precision detection of toxic metal ions is one of the chief requirements today to combat environment pollution. Gold nanoparticles play a key role in this by assisting the development of smart sensors and detection agents. Their high surface to volume ratio and unique optical property facilitates the development of high sensitive analytical GNP based bio-sensing tools. Recently, a major research thrust area has been the design and development of smartly fabricated GNPs as probes for selective detection of toxic contaminates and metal pollutants. In this review we focus on the use of GNPs and its functionalization for colorimetric detection of metal ions. Colorimetric detection enables cost effective and simple monitoring of toxic ions accompanied with the advantages of on-site applicability, avoids complex instrumentation, ease of analysis and usage. We also discuss the promising prospects and future potentiality of GNPs to serve as next generation multi-functional sensing tools and “lab-on-chip” detection agents.

Gold nanoparticles as efficient sensors in colorimetric detection of toxic metal ions: A review

Stimuli-responsive bio-based polymeric systems are gaining considerable attention as intelligent versatile tools that show great potential in various fields. In this review, an overview is given of recent developments of stimuli-responsive bio-based polymeric systems. The characteristics of bio-based polymers in different applications are discussed and the superiority of these advanced stimuli-responsive bio-based polymeric systems is highlighted. Furthermore, several emerging applications of these systems including intelligent drug delivery, responsive food packaging and smart water treatment are discussed and the section of intelligent drug delivery is emphasized in detail. Finally, the respective prospects and limitations inherent to these systems are addressed.

Stimuli-responsive bio-based polymeric systems and their applications

Cellulose is the most abundant biomass material in nature, and possesses some promising properties, such as mechanical robustness, hydrophilicity, biocompatibility, and biodegradability. Thus, cellulose has been widely applied in many fields. "Smart" materials based on cellulose have great advantages-especially their intelligent behaviors in reaction to environmental stimuli-and they can be applied to many circumstances, especially as biomaterials. This review aims to present the developments of "smart" materials based on cellulose in the last decade, including the preparations, properties, and applications of these materials. The preparations of "smart" materials based on cellulose by chemical modifications and physical incorporating/blending were reviewed. The responsiveness to pH, temperature, light, electricity, magnetic fields, and mechanical forces, etc. of these "smart" materials in their different forms such as copolymers, nanoparticles, gels, and membranes were also reviewed, and the applications as drug delivery systems, hydrogels, electronic active papers, sensors, shape memory materials and smart membranes, etc. were also described in this review.

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“Smart” Materials Based on Cellulose: A Review of the Preparations, Properties, and Applications

Electrospun membrane of cellulose acetate for heavy metal ion adsorption in water treatment

A colorimetric sensor for determination of cysteine by carboxymethyl cellulose-functionalized gold nanoparticles

Synthesis, self-assembly and drug release behaviors of pH-responsive copolymers ethyl cellulose-graft-PDEAEMA through ATRP

The self-assembly and pH- and thermo-sensitivities properties of hydroxypropyl cellulose-graft-poly(N,N-dimethyl aminoethyl methacrylate) (HPC-g-PDMAEMA) copolymers in aqueous solutions were investigated by transmittance, dynamic light scattering (DLS), and 1H NMR spectroscopy. Micelles with different structure can be formed by varying either pH value or temperature. At low pH, e.g., 3.0, the HPC backbone of the copolymer collapse to form the core of micelles stabilized with protonated PDMAEMA side chains on the surface of the micelles upon heating. At the medium pH, e.g., 8.1, both HPC backbone and PDMAEMA side chains collapse upon heating to form unstable aggregates. At high pH, e.g., 12.3, PDMAEMA side chains collapse first to form the core of micelles stabilized with HPC chains upon heating. Further heating the copolymer solution at this pH leads to the aggregation of the micelles due to the collapse of the shell HPC chains. The thermal sensitivity of the HPC-g-PDMAEMA copolymers is reversible.

Self-Assembly and Dual-Stimuli Sensitivities of Hydroxypropylcellulose-graft-poly(N,N-dimethyl aminoethyl methacrylate) Copolymers in Aqueous Solution

A pH-sensitive gold nanoparticle-cysteamine/carboxymethyl cellulose (Au-CA/CMC) dispersion system was prepared by a simple approach. Gold nanoparticles (AuNPs) were first synthesized by directly reducing chloroauric acid (HAuCl(4)) with sodium carboxymethyl cellulose (CMC). Then the AuNPs were decorated by an electrostatic compound of cysteamine hydrochloride (CA) and sodium carboxymethyl cellulose (CMC) through ligand exchange to get the assembly of Au-CA/CMC. The Au-CA/CMC dispersion system exhibits strongly reversible pH-responsive behavior with the aggregation of AuNPs caused by the combined action of the chain conformation change of CMC and electrostatic interactions between CA and CMC at different pH values. Finally, the reversible aggregation mechanism of AuNPs in the Au-CA/CMC dispersion system has been investigated by transmission electron microscopy (TEM) and ultraviolet-visible spectroscopy (UV-vis spectroscopy). This study provides a new method to fabricate a stimuli-responsive system free from complicated organic synthesis without using a toxic reducing agent.

Junjun Tan

Papers

Electrospun membrane of cellulose acetate for heavy metal ion adsorption in water treatment

A colorimetric sensor for determination of cysteine by carboxymethyl cellulose-functionalized gold nanoparticles

Synthesis, self-assembly and drug release behaviors of pH-responsive copolymers ethyl cellulose-graft-PDEAEMA through ATRP

Self-Assembly and Dual-Stimuli Sensitivities of Hydroxypropylcellulose-graft-poly(N,N-dimethyl aminoethyl methacrylate) Copolymers in Aqueous Solution

Controllable aggregation and reversible pH sensitivity of AuNPs regulated by carboxymethyl cellulose.