Development of stimulus-sensitive electrospun membranes based on novel biodegradable segmented polyurethane as triggered delivery system for doxorubicin

Redox/NIR dual-responsive glutathione extended polyurethane urea electrospun membranes for synergistic chemo-photothermal therapy

Despite advancements in cancer treatments, therapies frequently exhibit high cytotoxicity, and surgery remains the predominant method for treating most solid tumors, often with limited success in preventing post-surgical recurrence. Implantable biomaterials, designed to release drugs at a localised site in response to specific stimuli, represent a promising approach for enhancing tumour therapy. In this study, a redox-responsive glutathione extended polyurethane urea (PolyCEGS) was used to produce paclitaxel (PTX) and gold nanorods (AuNRs) loaded electrospun membranes for combined redox/near-infrared (NIR) light-responsive release chemotherapy and hyperthermic effect. Electrospinning conditions were optimized to fabricate AuNR-loaded scaffolds, at three different AuNRs concentrations. The obtained membranes were characterized by scanning electron microscopy (SEM) analyses and photothermal profiles were evaluated by a thermocamera, showing a temperature increase, up to 42.5 °C, when exposed to NIR light (810 nm) at 3 W/cm2. The AuNRs/PTX loaded scaffolds exhibited sustained PTX release, with 15 % released over 30 days and almost 1.8 times more in a simulated reductive environment. Moreover, their excellent photothermal effects and NIR light-triggered release led to significant synergic cytotoxicity in human colon cancer (HCT-116) and human breast cancer (MCF-7) cell lines. This system potentially enables controllable locoregional PTX release at the tumour site post-surgery, preventing recurrence and enhancing cytotoxicity through combined drug and PTT effects, highlighting its potential for future anticancer treatments.

Targeted Chemo-Phototherapy in Red Light with Novel Doxorubicin and Iron(III) Complex-Functionalized Gold Nanoconjugate (Dox-Fe@FA-AuNPs)

The anticancer efficacy of doxorubicin, an anthracycline-based and FDA-approved chemotherapeutic drug, is significantly hindered by acquired chemoresistance and severe side effects despite its potent anticancer properties. To overcome these challenges, we developed an innovative therapeutic formulation that integrates targeted chemotherapy and phototherapy within a single platform using gold nanoparticles (AuNPs). This novel nanoconjugate, designated as Dox-Fe@FA-AuNPs, is co-functionalized with folic acid, doxorubicin, and an iron(III)-phenolate/carboxylate complex, enabling cancer-specific drug activation. Here, we report the synthesis, characterization, and comprehensive physico-chemical and biological evaluations of Dox-Fe@FA-AuNPs. The nanoconjugate exhibited excellent solubility, stability, and enhanced cellular uptake in folate receptor-positive cancer cells. The nanoconjugate was potently cytotoxic against HeLa and MDA-MB-231 cancer cells (HeLa: 105.5±16.52 μg mL-1; MDA-MB-231: 112.0±12.31 μg mL-1; MDA-MB-231 (3D): 156.31±19.35 μg mL-1) while less cytotoxic to the folate(-) cancer cells (MCF-7, A549 and HepG2). The cytotoxicity was attributed to the pH-dependent release of doxorubicin, which preferentially occurs in the acidic tumor microenvironment. Additionally, under red light irradiation, the nanoconjugate generated ROS, inducing caspase-3/7-dependent apoptosis with a photo-index (PI) >50, and inhibited cancer cell migration. Our findings underscore the potential of Dox-Fe@FA-AuNPs as a highly effective and sustainable platform for targeted chemo-phototherapy.

Stimuli-responsive electrospun nanofibers for drug delivery, cancer therapy, wound dressing, and tissue engineering

The stimuli-responsive nanofibers prepared by electrospinning have become an ideal stimuli-responsive material due to their large specific surface area and porosity, which can respond extremely quickly to external environmental incitement. As an intelligent drug delivery platform, stimuli-responsive nanofibers can efficiently load drugs and then be stimulated by specific conditions (light, temperature, magnetic field, ultrasound, pH or ROS, etc.) to achieve slow, on-demand or targeted release, showing great potential in areas such as drug delivery, tumor therapy, wound dressing, and tissue engineering. Therefore, this paper reviews the recent trends of stimuli-responsive electrospun nanofibers as intelligent drug delivery platforms in the field of biomedicine.

Polybutylene Succinate Processing and Evaluation as a Micro Fibrous Graft for Tissue Engineering Applications

A microfibrous tubular scaffold has been designed and fabricated by electrospinning using poly (1,4-butylene succinate) as biocompatible and biodegradable material. The scaffold morphology was optimized as a small diameter and micro-porous conduit, able to foster cell integration, adhesion, and growth while avoiding cell infiltration through the graft's wall. Scaffold morphology and mechanical properties were explored and compared to those of native conduits. Scaffolds were then seeded with adult normal human dermal fibroblasts to evaluate cytocompatibility in vitro. Haemolytic effect was evaluated upon incubation with diluted whole blood. The scaffold showed no delamination, and mechanical properties were in the physiological range for tubular conduits: elastic modulus (17.5 ± 1.6 MPa), ultimate tensile stress (3.95 ± 0.17 MPa), strain to failure (57 ± 4.5%) and suture retention force (2.65 ± 0.32 N). The shown degradation profile allows the graft to provide initial mechanical support and functionality while being colonized and then replaced by the host cells. This combination of features might represent a step toward future research on PBS as a biomaterial to produce scaffolds that provide structure and function over time and support host cell remodelling.