Lab

Gabriel Luna-Barcenas's Lab


About the lab

Polymer & Biopolymer Research Group

Featured research (41)

Producing reduced graphene oxide (rGO) from oxidizing agents is an efficient, low-cost, and mass-production method. However, conventional reducing agents are highly toxic and harmful to the environment. Our work proposes an eco-friendly and facile method for the synthesis of rGO from graphene oxide (GO) using green reducing agents, such as basic amino acids (AAbs), including L-arginine (Arg), l-lysine (Lys), and L-histidine (His), induced by ultrasound cavitation (US). The chemical characterization, conducted through FTIR and XPS, revealed the disappearance of the signals corresponding to the oxygenated groups of GO and the formation of sp2 carbon. Additionally, the XPS technique demonstrated an increase in the C/O ratio, indicating the formation of rGO. The UV–Vis spectroscopy indicated the energetic transitions involved in the rGO; XRD was employed to ascertain the structural characteristics of the obtained materials, including the crystal size, number of layers, and degree of reduction. TGA was utilized to evaluate the thermal stability, focusing on the second loss (T2), which corresponds to the oxygenated groups. Cyclic voltammetry (CV) determined the electrochemically active surface area. All the catheterizations exhibited superior outcomes when the green reducing agent was combined with the ultrasound cavitation. The use of Lys as the reducing agent was highlighted, indicating that the combination of techniques reduced the time required to reduce GO, thereby enhancing the efficiency of the methods.
This study presents an entirely experimental and mathematical analysis of extrusion and melt spinning to obtain polyethylene terephthalate (PET) fibers. In addition, results concerning the design and construction of a quench system were investigated. PET fibers were obtained from two raw materials: postconsumer PET thermoform packaging (R-PET) and virgin PET (V-PET). The mathematical analysis part for the extruder contemplated a melt flow model based on the Navier–Stokes constitutive equations for a rectangular coordinate in the z-direction to predict the extruded mass flow depending on processing conditions (temperature and extrusion speed) and physical properties of raw material (intrinsic viscosity and density). Concerning the spinning process, a rheological model based on the Phan–Thien and Tanner (PTT) constitutive equations was used for the simulation of the dynamic flow of postconsumer PET thermoform packaging, including the combined effects of material flow, filament cooling, air drag, surface tension, and gravity to determine the necessary quench system length to cooling melt PET fiber down to their glass transition temperature (Tg), as well as axial velocity, filament diameter, and filament temperature profiles along all draw region of the spinning process. For this, it was necessary to fabricate and evaluate three different quench system designs to ensure a uniform air velocity profile along all cooling systems. The experimental analysis contemplated all critical steps for PET fiber fabrication, such as extrusion and spinning processes. This physical and chemical characterization of raw material, extruded PET, and fabricated PET fibers were obtained. Finally, the experimental data were used to validate both mathematical models. Proper sorting of PET thermoforms, removing impurities, and appropriately operating conditions for the extrusion and spinning processes allowed us to obtain elongation at yield, Young’s modulus, and tenacity values of 4.18%, 5568.1 Kgf/cm2, and 0.94 gf/den for V-PET fibers and 7.11%, 4795 Kgf/cm2, and 0.7 gf/den for R-PET fibers, respectively.
The deproteinization of chitosan is a necessary purification process for materials with biomedical purposes; however, chitosan sourcing and purification methods can modify its molecular weight, deacetylation degree, and residual proteins. These factors affect the reactive groups that affect the immunomodulatory activities of cells, particularly macrophages and monocytes; considering this activity is key when developing successful and functional biomaterials. Here, two brands of chitosan were purified and used to synthesize nanoparticles to evaluate their immunomodulatory effect on monocyte and macrophage differentiation. Chitosan FT-IR showed bands related to its purification process, with increased OH group intensity. Nanoparticles (CtsNps) synthesized with purified chitosan were of a smaller size compared to those using unpurified chitosan due to the alkaline purification process's shortening of the polymeric chain. At low concentrations (50 µg/mL), CtsNps showed a lower expression of CD80 and CD14, corroborating the differentiation effect of chitosan. Inducible nitric oxide synthase (iNOS) is related to a pro-inflammatory response and M1 macrophage polarization was detected in monocytes treated with purified and unpurified nanoparticles. Sigma-purified chitosan nanoparticles (CtsNps SigmaP), at 300 µg/mL, showed arginase production related to an anti-inflammatory response and M2 macrophage polarization. The chitosan purification process induces a shift in the polarization of macrophages to an anti-inflammatory M2 profile. This effect is concentration-dependent and should be further studied in each use case to favor the suitable biological response.
Our work evaluates the impact of crystallization rate during the synthesis of α-MoO3 nanorods and their bactericidal performance against Gram (+) S. aureus and Gram (−) E. coli. For this purpose, α-MoO3 nanorods were synthesized by varying the crystallization times to 12, 24, and 48 h. XRD patterns reveal that crystallization time changes crystal size. The growth of α-MoO3 does not show chemical modifications. However, SEM and TEM reveal the characteristic nanorods morphology, where the crystallization times affect the diameter. Crystal growth also changes the atomic percentage of Mo/O, which is determined by XPS. The above was reflected in the antibacterial performance of α-MoO3, evaluated at different nanoparticle concentrations (0.5–4 mg/mL). The α-MoO3 is an efficacious antibacterial for both pathogens by the enhanced crystal size, with higher bactericidal performance against Gram-positive bacteria, indicating that the rod architecture improves their interaction through electrostatic attraction with the peptidoglycan structure of S. aureus bacteria. In addition, electrochemical measurements indicate that the electroactive area of α-MoO3 plays a key role in the nanoparticle/bacteria interaction. As a result, the intrinsic characteristics of α-MoO3 nanorods, including crystal size, morphology, nanorod diameter, oxygen vacancies, and EASA, influence the antibacterial activity, generating materials with potential biomedical applications.
This study investigated the potential of self-nanoemulsifying drug delivery systems (SNEDDS) to optimize the oral bioavailability of insulin. Insulin complexes with phospholipids and enzymatically-modified phospholipids were developed and incorporated into the SNEDDS using Lauroglycol FCC as the oily phase and Cremophor EL and Labrafil M1944CS as the surfactant and co-surfactant, respectively. Additionally, mucoadhesive polysaccharides (sodium alginate and guar gum) were added further to enhance the bioavailability of insulin in these systems. The objective was to increase the bioavailability and bioactivity of an insulin-modified phosphatidylcholine complex by incorporating mucoadhesives into the SNEDDS. After polymer inclusion, the resulting nanoemulsions exhibited droplet diameters ranging from 57 to 83 nm. Cytotoxicity and apparent permeability tests were conducted on Caco-2 and NIH 3T3 cell lines, revealing that toxicity was related to the concentrations of insulin and surfactant in the nanosystems—formulations containing guar gum as a mucoadhesive showed better tolerance to cell death in the Caco-2 line. In a murine diabetes model, the SNEDDS were observed to reduce glucose levels by up to 61.63%, with a relative bioavailability of 2.25% compared to subcutaneously administered insulin. These results suggest that SNEDDS incorporating mucoadhesives could represent a promising strategy for improving oral insulin delivery.

Lab head

Gabriel Luna-Barcenas
Department
  • Institute of Advanced Materials for Sustainable Manufacturing
About Gabriel Luna-Barcenas
  • Bionanocomposites for Tissue Engineering; Biosensors; Molecular relaxation in nanocomposites; nanoemulsions as drug delivery systems

Members (6)

Yevgen Prokhorov
  • Center for Research and Advanced Studies of the National Polytechnic Institute
Yuriy Kovalenko
  • MSOLab; Cinvestav QRO
Olimpia Arias de Fuentes
  • University of Havana
Araceli Mauricio
  • Center for Research and Advanced Studies of the National Polytechnic Institute
Blanca Estela Castillo
  • Center for Research and Advanced Studies of the National Polytechnic Institute