Aline Luiza Machado Carlos

Lipases catalyze lipid hydrolysis and are widely applied in the food, pharmaceutical, and biofuel industries. However, their practical use is limited by instability under harsh conditions such as high temperatures, extreme pH, and organic solvents. Immobilization in nanostructured materials has emerged as an effective strategy to enhance enzyme stability, activity, and reusability while reducing contamination. Among these approaches, core–shell structures enable efficient enzyme encapsulation and can be produced in a single step via Solution Blow Spinning (SBS).This study investigated the immobilization of Candida rugosa lipase in core–shell fiber mats produced by SBS. Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) fibers were modified with 1% (w/v) polyethylene glycol (PEG) as a pore-forming agent to improve substrate diffusion and catalytic performance. PEG incorporation increased enzyme accessibility, resulting in enhanced enzymatic activity.Immobilization also provided thermal protection at 50 °C and increased catalytic activity by up to twofold compared to the free enzyme (from 270.33 to 631.78 U/gP). At 37 °C and neutral pH, PHBV/PEG fibers exhibited approximately 30% higher relative activity (434.77 ± 83.02 U/gP) than the free enzyme (322.16 ± 35.17 U/gP). Reusability tests further demonstrated the advantages of immobilization, with residual activities of 10% and 1% after the first reuse cycle for PHBV/PEG and PHBV fibers, respectively.Overall, enzyme encapsulation via SBS represents a promising strategy for developing high-performance biocatalysts with improved stability, activity, and industrial applicability.

The regeneration of skin injuries can be aided by tissue engineering strategies, which enable the recovery of the structural and functional integrity of the damaged tissue. The Solution Blow Spinning (SBS) technique has attracted the attention of researchers due to the production of nanofiber mats in a continuous process, which exhibit high porosity and the ability to deliver drugs locally. The objective of this work was to produce and encapsulate ibuprofen in mats of PCL/PEG as a fast-acting analgesic drug delivery system. Initially, beaded nanofiber structures were produced from PCL solutions in chloroform at 8% (w/v) and PCL/PEG solutions in mass ratios of 2:1 and 1:1. The influence of the PEG concentration, gas pressure (compressed air), and solution injection rate on the fibers' morphology was analyzed by SEM. Then, the best condition for the formation of PCL/PEG beaded fiber structure was selected (1:1, 137.90 kPa, and 7.2 mL/h) for the fabrication of the mat containing ibuprofen at proportions of 5, 15, and 30% by polymer mass (PCL/PEG). The SBS-spun mats demonstrated a remarkable swelling capacity of approximately 400%, with bead presence enabling a gradual release of ibuprofen within the first 5 h. Additionally, the wound-healing assay confirmed that ibuprofen-loaded PCL/PEG₈ mats significantly promoted NF migration, suggesting their potential to accelerate the wound-healing process.

Electrospinning is a widely used technology for micro‐ and nanofibers production. However, when in situ fibers deposition or immobilization of specific agents is required, solution blow spinning (SBS) is a safer alternative. In this work, SBS system was used to produce core‐shell fibers with potential use in bioactive agent delivery. Two biodegradable polymers (poly(lactic acid) ‐ PLA and poly(3‐hydroxybutyrate‐co‐3‐hydroxyvalerate) – PHBV) were processed with different working distances and air pressure to evaluate the influence of these variables as well as the characteristics of polymers on the fiber morphology. PHBV fibers present the best morphology with fewer defects and beads, although these fibers show larger diameters (from 2.03 to 2.27 μm) compared to PLA fibers (from 0.54 to 2.03 μm). Moreover, deposition of PHBV fibers is not significantly affected by the processing variables, indicating stability under SBS processing. PHBV is firstly used as a matrix to encapsulate hydrophilic bioactive in core‐shell structure via SBS. This structure allows the sustained release of lipase even after 14 days, evidencing the efficiency of the core‐shell fibers in producing controlled release systems. Core‐shell aligned fibers with a reduced diameter (from 3.07 to 1.42 μm) are produced replacing the static target with a rotating collector.