Targeted delivery of low molecular drugs using chitosan and its derivatives.

Nanotechnology: The new perspective in precision agriculture.

Competitive adsorption of Pb(II), Cu(II) and Zn(II) onto xanthate-modified magnetic chitosan

Background: Synthetic nanoparticles are emerging as versatile tools in biomedical applications, particularly in the area of biomedical imaging. Nanoparticles 1 – 100 nm in diameter have dimensions comparable to biological functional units. Diverse surface chemistries, unique magnetic properties, tunable absorption and emission properties, and recent advances in the synthesis and engineering of various nanoparticles suggest their potential as probes for early detection of diseases such as cancer. Surface functionalization has expanded further the potential of nanoparticles as probes for molecular imaging. Objective: To summarize emerging research of nanoparticles for biomedical imaging with increased selectivity and reduced nonspecific uptake with increased spatial resolution containing stabilizers conjugated with targeting ligands. Methods: This review summarizes recent technological advances in the synthesis of various nanoparticle probes, and surveys methods to improve the targeting of nanoparticles for...

Nanoparticles for biomedical imaging

The interactions of proteins and polyelectrolytes lead to diverse applications in separations, delivery and wound repair, and are thus of interest to scientists in e.g. (a) glycobiology, (b) tissue engineering, (c) biosensing, and (d) pharmacology. This breadth is accompanied by an assortment of contexts and models in which polyelectrolytes are seen as (a) protein cognates assisting in complex cellular roles, (b) surrogates for the extracellular matrix, mimicking its hydration, mechanical and sequestering properties, (c) benign hosts that gently entrap, deposit and tether protein substrate specificity, and (d) selective but non-specific agents that modify protein solubility. Unsurprisingly, this literature is somewhat segregated by objectives and paradigms. We hope this review, which emphasizes publications over the last 8 years, represents and also counterbalances that divergence. An ongoing theme is the role of electrostatics, and we show how this leads to the variety of physical forms taken by protein–polyelectrolyte complexes. We present approaches towards analysis and characterization, motivated by the goal of structure–property elucidation. Such understanding should guide in applications, our third topic. We present recent developments in modeling and simulations of protein–polyelectrolyte systems. We close with a prospective on future developments in this field.

/pdf/protein-polyelectrolyte-interactions-3iskvzeg8j.pdf

Protein–polyelectrolyte interactions

Effect of molecular weight and ionic strength on the formation of polyelectrolyte complexes based on poly(methacrylic acid) and chitosan.

Particulate systems composed of polyelectrolyte complexes (PEC) based on chitosan and poly(methacrylic acid) were obtained via template polymerization. The resultant particles were characterized as having regions with different charge densities:  chitosan predominating in the core and poly(methacrylic acid) at the surface, the particles being negatively charged, as a consequence. Albumin was adsorbed on these particles (after cross-linking with glutardialdehyde), and pH was controlled to obtain two conditions:  (i) adsorption of positively charged albumin and (ii) adsorption of albumin at its isoelectric point. Adsorption isotherms and ζ-potential measurements showed that albumin adsorption was controlled by hydrogen bonding/van der Waals interactions and that brush-like structures may enhance the adsorption of albumin on these particles. It was also found that shearing can induce desorption of albumin from the PEC surface, depending on the continuous phase albumin concentration.

P. M. Bezerril

Papers

Effect of molecular weight and ionic strength on the formation of polyelectrolyte complexes based on poly(methacrylic acid) and chitosan.

Adsorption of Bovine Serum Albumin on Template-Polymerized Chitosan/Poly(methacrylic acid) Complexes

Viscosity-temperature behavior of chitin solutions using lithium chloride/DMA as solvent.