Preparation and characterization of porous biodegradable microspheres used for controlled protein delivery

A biodegradable polymeric system for peptide–protein delivery assembled with porous microspheres and nanoparticles, using an adsorption/infiltration process

“…Similar results have been reported when serum albumin is adsorbed onto PLGA microspheres. 16 Adsorption involves electrostatic and hydrophobic interactions, so physiochemical properties like pH, ionic strength, and temperature play an important role in peptide-protein adsorption. 24,25 A pH of 7.2 in the dipping solution creates an environment in which charged species exist; consequently, electrostatic interactions among the components are present in the adsorption process.…”

“…This finding can be associated with the leuprolide that was adsorbed onto the more superficial zone of the porous structure, since it is in immediate contact with the dissolution medium and thus enables the desorption process. 16,21,29 Therefore, porosity and surface area play an important role in peptide release. However, at close to 12 hours, system 1 (without adsorbed nanoparticles) had released 90.3% ± 9.1% of the peptide, whereas systems 2, 3, 4, and 5 (with adsorbed nanoparticles) had released only 36.1% ± 5.2%, 29.4% ± 3.2%, 22.2% ± 4.6%, and 19.8% ± 3.2%, respectively (see Figure 8).…”

“…15,16 Despite the advantages of using polymeric micro-and nanocarriers for peptide-protein delivery, there is an inherent instability in these molecules at each step of the manufacturing process. First, peptide-protein loading involves the use of organic solvents that generate changes in the physicochemical properties of the peptide-protein, while the interfaces in the emulsification stage may cause unfolding and aggregation through interfacial adsorption.…”

Microemulsions - A Brief Introduction

“…Among them is the delivering of genes into the cells (Gupta et al, 2004), with the aim of treatment of disease or diagnosis (Pedersen et al, 2006, Peng et al, 2006, Xu et al, 2011, Rossi et al, 2006, Santra et al, 2005, targeting cancer cell (Tao et al, 2011, Lu et al, 2008, Reithofer et al, 2011, act as vaccine (Sun et al, 2009, Mumper & Cui, 2003, biocatalyss (Stamatis & Xenakis, 1999, Zoumpanioti et al, 2010, Blattner et al, 2006, cosmetics (Chiu & Yang, 1992, Förster et al, 1995, Valenta & Schultz, 2004, Teichmann et al, 2007 or changing the genetic to improve the performance of the targeted cells , Courrier et al, 2004.…”

Studies on the preparation and in vitro - in vivo evaluation of mucoadhesive microspheres of glycyrrhetinic acid isolated from liquorice

“…The mucoadhesion is the adhesive interactions between polymers and mucus or mucosal surfaces. It refers to the state in which two surfaces, at least one biological in nature gets held together in close contact by interfacial forces for an extended duration of time (Chun et al, 2005b;Chun et al, 2005a;, Soane et al, 1999;Sun et al, 2009). …”