Preparation of letrozole dispersed pHEMA/AAm-g-LDPE drug release system: In-vitro release kinetics for the treatment of endometriosis

A Novel Intrauterine Device for the Spatio-Temporal Release of Norethindrone Acetate as a Counter-Estrogenic Intervention in the Genitourinary Syndrome of Menopause

The genitourinary syndrome of menopause (GSM) is a widely occurring condition affecting millions of women worldwide. The current treatment of GSM involves the use of orally or vaginally administered estrogens, often with the risk of endometrial hyperplasia. The utilization of progestogens offers a means to counteract the effects of estrogen on the endometrial tissue, decreasing unwanted side effects and improving therapeutic outcomes. In this study, a norethindrone acetate (NETA)-loaded, hollow, cylindrical, and sustained release platform has been designed, fabricated, and optimized for implantation in the uterine cavity as a counter-estrogenic intervention in the treatment of GSM. The developed system, which comprises ethyl cellulose (EC) and polycaprolactone (PCL), has been statistically optimized using a two-factor, two-level factorial design, with the mechanical properties, degradation, swelling, and in vitro drug release of NETA from the device evaluated. The morphological characteristics of the platform were further investigated through scanning electron microscopy in addition to cytocompatibility studies using NIH/3T3 cells. Results from the statistical design highlighted the platform with the highest NETA load and the EC-to-PCL ratio that exhibited favorable release and weight loss profiles. The drug release data for the optimal formulation were best fitted with the Peppas-Sahlin model, implicating both diffusion and polymer relaxation in the release mechanism, with cell viability results noting that the prepared platform demonstrated favorable cytocompatibility. The significant findings of this study firmly establish the developed platform as a promising candidate for the sustained release of NETA within the uterine cavity. This functionality serves as a counter-estrogenic intervention in the treatment of GSM, with the platform holding potential for further advanced biomedical applications.

Synthesis and Characterization of Folic Acid-Functionalized DPLA-co-PEG Nanomicelles for the Targeted Delivery of Letrozole

An effective treatment for hormone-dependent breast cancer is chemotherapy using cytotoxic agents such as letrozole (LTZ). However, most anticancer drugs, including LTZ, are classified as class IV biopharmaceuticals, which are associated with low water solubility, poor bioavailability, and significant toxicity. As a result, developing a targeted delivery system for LTZ is critical for overcoming these challenges and limitations. Here, biodegradable LTZ-loaded nanocarriers were synthesized by solvent emulsification evaporation using nanomicelles prepared with dodecanol-polylactic acid-co-polyethylene glycol (DPLA-co-PEG). Furthermore, cancer cell-targeting folic acid (FA) was conjugated into the nanomicelles to achieve a more effective and safer cancer treatment. During our investigation, DPLA-co-PEG and DPLA-co-PEG-FA displayed a uniform and spherical morphology. The average diameters of DPLA-co-PEG and DPLA-co-PEG-FA nanomicelles were 86.5 and 241.3 nm, respectively. Our preliminary data suggest that both nanoformulations were cytocompatible, with ≥90% cell viability across all concentrations tested. In addition, the amphiphilic nature of the nanomicelles led to high drug loading and dispersion in water, resulting in the extended release of LTZ for up to 50 h. According to the Higuchi model, nanomicelles functionalized with FA have a greater potential for the controlled delivery of LTZ into target cells. This model was confirmed experimentally, as LTZ-containing DPLA-co-PEG-FA was significantly and specifically more cytotoxic (up to 90% cell death) toward MCF-7 cells, a hormone-dependent human breast cancer cell line, when compared to free LTZ and LTZ-containing DPLA-co-PEG. Furthermore, a half-maximal inhibitory concentration (IC50) of 87 ± 1 nM was achieved when MCF-7 cells were exposed to LTZ-containing DPLA-co-PEG-FA, whereas higher doses of 125 ± 2 and 100 ± 2 nM were required for free LTZ and LTZ-containing DPLA-co-PEG, respectively. Collectively, DPLA-co-PEG-FA represents a promising nanosized drug delivery system to target controllably the delivery of drugs such as chemotherapeutics.

Nanocomposite scaffolds composed of Apacite (apatite-calcite) nanostructures, poly (ε-caprolactone) and poly (2-hydroxyethylmethacrylate): The effect of nanostructures on physico-mechanical properties and osteogenic differentiation of human bone marrow mesenchymal stem cells in vitro

Nanocomposite scaffolds were fabricated from poly (ε-caprolactone) (PCL), Poly (2-hydroxyethylmethacrylate) (PHEMA), and Apacite (Apatite-calcite) nanostructures (15 and 25 wt%). The nanoscale structure, physical and chemical properties, mechanical properties, hydrophilic behavior, degradability and osteogenic properties of the fabricated scaffolds were evaluated. The results showed that the mechanical strength, degradation, wetting ability, and mechanical strength of PCL-PHEMA scaffolds significantly increases upon inclusion of Apacite nanoparticles up to 25 wt%. Accordingly, the best mechanical values (E ~ 7.109 MPa and σ ~ 0.414 MPa) and highest degradability (32% within 96 h) were recorded for PCL-PHEMA scaffolds containing 25 wt% of Apacite. Furthermore, highest porosity and roughness were observed in the PCL-PHEMA/25% Apacite as a result of the Apacite nanoparticles inclusion. There was no cytotoxicity recorded for the fabricated scaffolds based on the results obtained from MTT assay and acridine orange staining. Alkaline phosphatase activity, calcium content quantification, Van Kossa staining, FESEM and real time PCR tests confirmed the biomineralization, and the differentiation potential of the nanocomposite scaffolds. Overall, the 3D structure, optimum porosity and balanced dissolution rate of PCL-PHEMA/25% Apacite providing a balanced microenvironment resulted in improved cell adhesion, cell behavior, and replication, as well as osteogenic induction of human bone-marrow-derived mesenchymal stem cells (hBM-MSCs).