In Silico Study of Novel Cyclodextrin Inclusion Complexes of Polycaprolactone and Its Correlation with Skin Regeneration.

Three novel biomaterials obtained via inclusion complexes of ß-cyclodextrin, 6-deoxi-6-amino-ß-cyclodextrin and epithelial growth factor grafted to 6-deoxi-6-amino-ß-cyclodextrin with polycaprolactone. Furthermore, some physicochemical, toxicological and absorption properties were predicted using bioinformatics tools. The electronic, geometrical and spectroscopical calculated properties agree with the properties obtained via experimental methods, explaining the behaviors observed in each case. The interaction energy was obtained, and its values were -60.6, -20.9 and -17.1 kcal/mol for ß-cyclodextrin/polycaprolactone followed by the 6-amino-ß-cyclodextrin-polycaprolactone complex and finally the complex of epithelial growth factor anchored to 6-deoxy-6-amino-ß-cyclodextrin/polycaprolactone. Additionally, the dipolar moments were calculated, achieving values of 3.2688, 5.9249 and 5.0998 Debye, respectively, and in addition the experimental wettability behavior of the studied materials has also been explained. It is important to note that the toxicological predictions suggested no mutagenic, tumorigenic or reproductive effects; moreover, an anti-inflammatory effect has been shown. Finally, the improvement in the cicatricial effect of the novel materials has been conveniently explained by comparing the poly-caprolactone data obtained in the experimental assessments.

Gold Nanoparticles as Drug Carriers: The Role of Silica and PEG as Surface Coatings in Optimizing Drug Loading.

The use of gold nanoparticles as drug delivery systems has received increasing attention due to their unique properties, such as their high stability and biocompatibility. However, gold nanoparticles have a high affinity for proteins, which can result in their rapid clearance from the body and limited drug loading capabilities. To address these limitations, we coated the gold nanoparticles with silica and PEG, which are known to improve the stability of nanoparticles. The synthesis of the nanoparticles was carried out using a reduction method. The nanoparticles' size, morphology, and drug loading capacity were also studied. The SEM images showed a spherical and homogeneous morphology; they also showed that the coatings increased the average size of the nanoparticles. The results of this study provide insight into the potential of gold nanoparticles coated with silica and PEG as drug delivery systems. We used ibuprofen as a model drug and found that the highest drug load occurred in PEG-coated nanoparticles and then in silica-coated nanoparticles, while the uncoated nanoparticles had a lower drug loading capacity. The coatings were found to significantly improve the stability and drug load properties of the nanoparticles, making them promising candidates for further development as targeted and controlled release drug delivery systems.

Stiff-Elongated Balance of PLA-Based Polymer Blends.

In this study, polymer blends with a mechanical property balance based on poly(lactic acid) (PLA), stiff polymer, and elongated polymer were developed. First, the binary blends PLA-elongated polymer [ethyl vinyl acetate (EVA) or polyethylene], or PLA-stiff polymer [polystyrene or poly(styrene-co-methyl methacrylate) (SMMA)] blends were studied using dynamic mechanic analysis (DMA) and analyzed using Minitab statistical software to determine the factors influencing the elongation or stiffness of the blends. Then, ternary blends such as elongation-poly(lactic acid)-stiff, were made from the binary blends that presented optimal performance. In addition, three blends [EVA-PLA-SMMA (EPS)] were elaborated by studying the mixing time (5, 15, and 15 min) and the added time of the SMMA (0, 0, and 10 min). Specifically, the mixing time for EPS 1, EPS 2, and EPS 3 is 5 min, 15 min, and 15 min (first EVA + PLA for 10 min, plus 5 min PLA-EVA and SMMA), respectively. Mechanical, thermal, rheological, and morphological properties of the blends were studied. According to DMA, the results show an increase in elongation at break (εb) and do not decrease the elastic module of poly(lactic acid). Nevertheless, EPS 3 excels in all properties, with an εb of 67% and modulus of elasticity similar to PLA. SMMA has a significant role as a compatibilizing agent and improves PLA processability.

Biointeraction of Erythrocyte Ghost Membranes with Gold Nanoparticles Fluorescents.

The application of new technologies for treatments against different diseases is increasingly innovative and effective. In the case of nanomedicine, the combination of nanoparticles with biological membranes consists of a "camouflage" technique, which improves biological interaction and minimizes the secondary effects caused by these remedies. In this work, gold nanoparticles synthesized by chemical reduction (Turkevich ≈13 nm) were conjugated with fluorescein isothiocyanate to amplify their optical properties. Fluorescent nanoparticles were deposited onto the surface of hemoglobin-free erythrocytes. Ghost erythrocytes were obtained from red blood cells by density gradient separation in a hypotonic medium and characterized with fluorescence, optical, and electron microscopy; the average size of erythrocyte ghosts was 9 µm. Results show that the functional groups of sodium citrate (COO-) and fluorophore (-N=C=S) adhere by electrostatic attraction to the surface of the hemoglobin-free erythrocyte membrane, forming the membrane-particle-fluorophore. These interactions can contribute to imaging applications, by increasing the sensitivity of measurement caused by surface plasmon resonance and fluorescence, in the context of biological membranes.

Epithelial Growth Factor-Anchored on Polycaprolactone/6-deoxy-6-amino-ß-cyclodextrin Nanofibers: In Vitro and In Vivo Evaluation.

Polycaprolactone (PCL) is a well-known FDA approved biomaterial for tissue engineering. However, its hydrophobic properties limit its use for skin wound healing which makes its functionalization necessary. In this work, we present the fabrication and evaluation of PCL nanofibers by the electrospinning technique, as well as PCL functionalized with 6-deoxy-6-amino-ß-cyclodextrin (aminated nanofibers). Afterwards, epithelial growth factor (EGF) was anchored onto hydrophilic PCL/deoxy-6-amino-ß-cyclodextrin. The characterization of the three electrospun fibers was made by means of field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR); Confocal-Raman Spectroscopy were used for elucidated the chemical structure, the hydrophilicity was determined by Contact Angle (CA). In vitro cell proliferation test was made by seeding embryonic fibroblast cell line (3T3) onto the electrospun mats and in vivo studies in a murine model were conducted to prove its effectivity as skin wound healing material. The in vitro studies showed that aminated nanofibers without and with EGF had 100 and 150% more cell proliferation of 3T3 cells against the PCL alone, respectively. In vivo results showed that skin wound healing in a murine model was accelerated by the incorporation of the EGF. In addition, the EGF had favorable effects in epidermal cell proliferation. The study demonstrates that a protein of high biological interest like EGF can be attached covalently to the surface of a synthetic material enriched with amino groups. This kind of biomaterial has a great potential for applications in skin regeneration and wound healing.

Synthesis of Controlled-Size Silica Nanoparticles from Sodium Metasilicate and the Effect of the Addition of PEG in the Size Distribution.

Silica nanoparticles are widely studied in emerging areas of nanomedicine because they are biocompatible, and their surface can be modified to provide functionalization. The size is intrinsically related to the performance of the silica nanoparticles; therefore, it is important to have control over the size. However, the silica nanoparticles obtained from sodium metasilicate are less studied than those obtained from tetraethyl orthosilicate. Moreover, the methods of surface modification involve several steps after the synthesis. In this work, the effect of different concentrations of sodium metasilicate on the size of silica nanoparticles was studied. In the same way, we studied the synthesis of organically modified silica nanoparticles in a one-step method, using poly(ethylene glycol). The nanoparticles were characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, and thermogravimetric analysis. It was found that the size distribution of the silica nanoparticles could be modified by changing the initial concentration of sodium metasilicate. The one-step surface-modification method caused a significant decrease in size distribution.