Poly(l-glutamic acid)-Decorated Hybrid Colloidal Particles from Complex Particle-Templated Silica Mineralization

Abstract

We report the synthesis of polyelectrolyte complex (PEC) particles by mixing the negatively and positively charged polyelectrolytes, poly(L-glutamic acid) (PGA) and poly(2-(N,N-diethylamino) ethylmethacrylate) (PDEAEMA), and the use of negatively charged PEC particles as colloidal templates for silica mineralization under ambient conditions. The structure and property of PEC particles, as well as polypeptide chain conformation, were found to depend on the mixing weight percentage, polymer molecular weight, and solution condition. The negatively charged PEC micelles can be deposited with silica without loss colloid stability, leading to PGA-decorated hybrid particles. These hybrid particles were negatively charged at neutral and basic condition and become positively charged, accompanying the conformational changes of the grafted PGA, upon decreasing pH below isoelectric points due to the protonation/deprotonation of PGA and PDEAEMA. Functional nanoparticles such as gold NPs could be incorporated using polypeptides as the mediating agents. These hybrid particles loaded with drug exhibited noticeable pH-responsive behavior with accelerated release at acidic condition, demonstrating the potential for use as pH-responsive delivery vehicles. This type of polypeptide-decorated hybrid particles represents an interesting class of organic-inorganic hybrids in which the functional properties of polypeptides such as biocompatibility, stimuli responsiveness, and directed growth of metal nanoparticles can be incorporated.

Constructing Biopolymer-Inorganic Nanocomposite through a Biomimetic Mineralization Process for Enzyme Immobilization

“…As shown in Figure 2b, the two main peaks near −100 ppm and −110.5 ppm are attributed to Q 3 [Si(OSi) 3 (OH)] and Q 4 [Si(OSi) 4 ] with relative percentages of 30.2% and 69.8% respectively, which suggests the formation of well-condensed silica under the catalysis of NH 2 -Alginate. These results are in good agreement with the previous report that the mineralized silica using amine-containing polymers as catalysis and template exhibited a Q 4 /Q 3 ratio from 1.0 to 2.5 [25,26,27,28,29]. …”

Reduction- and pH-Sensitive lipoic acid-modified Poly(l-lysine) and polypeptide/silica hybrid hydrogels/nanogels

“…DLS analysis revealed that discrete polypeptide/silica hybrid nanogels can be prepared, evidenced by little change in sizes before and after silica deposition ( Table 2). FTIR analysis confirmed the deposition of silica in the polypeptide nanogels, as evidenced by the presence of silica absorption bands (data not shown) [50,51]. TEM analysis showed that their sizes were comparable with those determinded by DLS analysis (Fig.…”

“…FTIR analysis confirmed the deposition of silica in the polypeptide hydrogels, as evidenced by the silica absorption bands at 469 (SieOeSi bend), 801 (SieOeSi symmetric stretch), 960 (SieOeH stretch), 1092 and 1207 cmÀ1 (SieOeSi antisymmetric stretch) (Fig. 5a) [50,51]. From SEM, FTIR, and EDX analyses, the results indicated that silicas were occluded in the gel network.…”

“…Three polypeptides, denoted as PLL 50 , PLL 90 and PLL 180 , were used as the starting precursors for the synthesis of PLL-g-Lipo. Upon substitution reaction, the lipoic group can replace a hydrogen atom on the amino group of PLL.…”

Comparing water-mediated hydrogen-bonding in different polyelectrolyte complexes

“…Additionally, their properties can be further tuned via formation conditions [2][3][4] or post-treatment modification. [5][6][7][8][9][10] As many important biological macromolecules, such as DNA, RNA, polypeptides or polysaccharides are highly charged PEs, PECs are also promising materials in the fields of biotechnology and medicine. 11 The role of water in hydrated PECs is of great importance for their thermal and mechanical properties.…”