This research aimed to assess protein bioaccessibility of traditionally (TN) or ohmic heating (OH)-nixtamalized sorghum tortillas using two sorghum varieties (82w21/8133) processed at several conditions (110/120 V, 85/90 ºC). The 82w21 variety (120 V/85 ºC) displayed the highest yield (1.82 kg tortilla/kg masa) and the best sensory parameters (rollability/puffiness). A higher tannin decrease (-27.77%) was obtained compared to TN. The highest protein bioaccessibility (58.23 %) was found for OH-tortillas at 60 min in the digestible fraction, while TN showed the highest permeation rates. Concluding, OH is an environmentally friendly procedure to obtain nixtamalized sorghum flours to manufacture highly-bioaccessible protein tortillas

The present work was to evaluate the formation of type III resistant starch in Hylon VII starch by the cycle’s extrusion process. The starch was subjected to three extrusion cycles. Starch viscosity, structural and thermal properties were determined. Results have shown that thermal properties had a decrease in the enthalpy, a decrease in the viscosity, and a loss in the crystallinity pattern because of the cycle’s extrusion. The type III resistant starch decreased for each extrusion cycle, due to the gelatinization process that occurred during the extrusion cycles.

Annually, the incidence of diabetic foot ulcers (DFUs) varies between 9.1 to 26.1 million worldwide, with numbers increasing each year. About 25% of diabetic patients develop DFUs, with near 70% of those requiring lower limb amputation. DFUs often fail to progress past the inflammatory phase due to increased bacterial colonization and recurrent infection. Over the last decades, technology breakthroughs have demonstrated the impact of bioactive 3D, fiber-based scaffolding systems in the treatment of DFUs (DOI: 10.1016/j.ijpharm.2021.120423). In the present project, co-axial wet-spun microfibrous scaffolds are proposed as drug delivery platforms for infection control in DFUs-prevalent bacteria infested environments.

Microfibers with a shell made of poly(vinyl alcohol) (PVA) at 10wt.% in water and a core of polycaprolactone (PCL) at 10wt.% in dimethylformamide were engineered via wet-spinning in a 8wt.% Na2SO4 and 4wt.% NaOH coagulation bath. Ceftazidime and vancomycin minimum bactericidal concentrations (MBC) against S. aureus and P. aeruginosa were determined at 32.0µg/mL and 7.8µg/mL, respectively. Antibiotics were loaded at 2×MBC at the shell of the microfibers. PCL was used to sustain the scaffolding structure and convey mechanical resilience, while PVA was used primarily as a drug carrier, maintaining a local moist environment and absorbing exudates. The microfibers co-axial structure was confirmed via brightfield microscopy. Both polymers and antibiotics presence were verified via Fourier-transform infrared spectroscopy (FTIR) and UV-visible spectroscopy, following antibiotic release up to 24h in phosphate buffer (PBS, pH 7.4). Artificial exudates were used to attest the scaffold swelling capacity and map its degradation profile. Scaffolds could maintain >80% of their mass up to 28 days of incubation in dynamic conditions. Antimicrobial testing revealed the drug diffusion abilities of the scaffolding system, forming zones of inhibition in single and co-culture settings. Time-kill kinetics studies established this drug delivery platform as effective for infection control in non-sterile DFUs-mimicking environments within a 24h period.

Chronic wounds (CW) are a worldwide concern, causing serious strives on the health and quality of patients’ life. In CW, human neutrophil elastase (HNE) enzyme gets highly expressed during inflammation, reaching abnormally elevated concentrations. Additionally, prevalence of Staphylococcus aureus-induced infections remains very high and difficult to treat. Considering these phenomena, a drug delivery system made of co-axial wet-spun fibers, loaded with the tetrapeptide Ala-Ala-Pro-Val (AAPV, a known inhibitor of HNE activity) and N-carboxymethyl chitosan (NCMC, responsive to neutral-basic pH’s, characteristic of CW and endowed with antibacterial features), was proposed.

AAPV was synthesized by solid-phase peptide synthesis, whereas NCMC was synthesized from low molecular weight chitosan in a chloroacetic acid mixture. HNE inhibition tests were conducted to establish the AAPV IC₅₀ in 1.50 µg/mL and the NCMC minimum bactericidal concentration (MBC) against S. aureus in 6.40 mg/mL. These determinations were used to establish fiber loading amounts. Core-shell structures were produced with 10% w/v polycaprolactone (PCL) at the core and 2% w/v sodium alginate (SA) solutions at the shell. NCMC was mixed with SA at 2xMBC so neutral-basic pH-triggered solubility (characteristic of CW) would allow pores to be opened in the outer layer for accessing the core, where AAPV was combined with PCL.

Fourier-transform infrared spectroscopy and brightfield microscopy were used to confirm the presence of the four components on the fibers and the co-axial architecture, respectively. Fibers presented maximum elongations of over 100%. Release kinetics studies conducted via UV-visible absorption spectroscopy mapped NCMC liberation overtime but were uncapable of detecting AAPV, since polymer degradation masked AAPV absorption peaks. Time-kill kinetics studies against S. aureus demonstrated the effectiveness of NCMC in eliminating this bacterium, particularly after 6 h of incubation. On its turn, AAPV guaranteed HNE inhibition. Data demonstrated the potential of SA-NCMC-PCL-AAPV co-axial systems to work as stepwise, pH-triggered delivery platforms.

A green chemistry approach was employed to develop gastric pH resistant bio-composites for colon targeted oral delivery of darfenacin hydrobromide. The FTIR, XRD, DSC and TGA results showed good drug-polymer compatibility. The SEM images showed calcite formation in the quince hydrogel system. The drug release of 80% and 34% were observed in a phosphate buffer 6.8 pH and an acidic media, respectively. The restricted drug permeation (approx. 21.8% only) was observed through gastric membrane in an acidic media. The developed formulation significantly inhibited the development of testosterone induced prostatic hyperplasia. No organ toxicity was observed against all the developed formulations.