Freeze-thaw electrospun PVA-dacarbazine nanoparticles: preparation, characterization and anticancer evaluation

Enhancing chemical and physical stability of pharmaceuticals using freeze-thaw method: challenges and opportunities for process optimization through quality by design approach

The freeze-thaw (F/T) method is commonly employed during the processing and handling of drug substances to enhance their chemical and physical stability and obtain pharmaceutical applications such as hydrogels, emulsions, and nanosystems (e.g., supramolecular complexes of cyclodextrins and liposomes). Using F/T in manufacturing hydrogels successfully prevents the need for toxic cross-linking agents; moreover, their use promotes a concentrated product and better stability in emulsions. However, the use of F/T in these applications is limited by their characteristics (e.g., porosity, flexibility, swelling capacity, drug loading, and drug release capacity), which depend on the optimization of process conditions and the kind and ratio of polymers, temperature, time, and the number of cycles that involve high physical stress that could change properties associated to quality attributes. Therefore, is necessary the optimization of F/T conditions and variables. The current research regarding F/T is focused on enhancing the formulations, the process, and the use of this method in pharmaceutical, clinical, and biological areas. The present review aims to discuss different studies related to the impact and effects of the F/T process on the physical, mechanical, and chemical properties (porosity, swelling capacity) of diverse pharmaceutical applications with an emphasis on their formulation properties, the method and variables used, as well as challenges and opportunities in developing. Finally, we review the experimental approach for choosing the standard variables studied in the F/T method applying the systematic methodology of quality by design.

Characterization of Gels and Films Produced from Pinhão Seed Coat Nanocellulose as a Potential Use for Wound Healing Dressings and Screening of Its Compounds towards Antitumour Effects

The reuse of agro-industrial waste assumes great importance today. Pinhão is the seed of Araucaria angustifolia, which is native to the mountains of southern Brazil, Paraguay, and Argentina. The coat is a by-product of this seed and is rich in phenolic compounds. The present study aimed to use the residue as a precursor material for the production of nanocellulose through the mechanical defibrillation process and perform the characterization of the films and the gel to investigate the effect on the physical and regenerative properties when incorporated with polyvinyl alcohol (PVA). The modulus of elasticity was higher when the MFC of pinhão was added to the PVA. Film and gel had their cytotoxicity tested by MTT assay using 3T3 fibroblast and Schwann cancer cells, and a migration assay was also performed using the scratch test on HaCat keratinocyte cells. For the scratch test, film and gel samples with low concentration presented a complete scratch closure in 72 h. Molecular docking was performed and quercetin had the ideal interaction score values, so it was used with the PACAP protein which presented a slightly moderate interaction with the protein synthesis of Schwann cells, presenting compactness of the compound after 14 ns.

Green synthesis of PEG-coated MIL-100(Fe) for controlled release of dacarbazine and its anticancer potential against human melanoma cells

In this study, the potential of using MIL-100(Fe) metal-organic framework (MOF) for loading and controlling the release of dacarbazine (DTIC) was evaluated for in vitro treatment of melanoma. The drug loading was performed during the green synthesis of MIL-100(Fe) in an aqueous media without using any harmful solvents, to obtain MIL-DTIC. The surface of this structure was then coated with polyethylene glycol (PEG) in the same aqueous solution to synthesize MIL-DTIC-PEG. The synthesized samples were characterized using various methods. Their release profile was studied in phosphate-buffered saline (PBS) and simulated cutaneous medium (SCM). The cytotoxicity of DTIC and its nano-MOF formulation were investigated against melanoma A375 cell lines. The results revealed that the PEG coating (PEGylation) changed the surface charge of MOF from -2.8 ± 0.9 mV to -42.8 ± 1.2 mV, which can contribute to the colloidal stability of MOF. The PEGylation showed a significant effect on controlled drug release, especially in SCM, which increases the complete release time from 60 h to 12 days. Moreover, both of the drug-containing MOFs showed more toxicity than DTIC and unloaded MOFs, confirming that the cumulative release of drug and better cellular uptake of NPs lead to increased toxicity.

Development, Characterization and Cell Viability Inhibition of PVA Spheres Loaded with Doxorubicin and 4'-Amino-1-Naphthyl-Chalcone (D14) for Osteosarcoma

Chalcones (1,3-diaryl-2-propen-1-ones) are naturally occurring polyphenols with known anticancer activity against a variety of tumor cell lines, including osteosarcoma (OS). In this paper, we present the preparation and characterization of spheres (~2 mm) from polyvinyl alcohol (PVA) containing a combination of 4′-Amino-1-Naphthyl-Chalcone (D14) and doxorubicin, to act as a new polymeric dual-drug anticancer delivery. D14 is a potent inhibitor of osteosarcoma progression and, when combined with doxorubicin, presents a synergetic effect; hence, physically crosslinked PVA spheres loaded with D14 and doxorubicin were prepared using liquid nitrogen and six freeze–thawing cycles. Physical-chemical characterization using a scanning electron microscope (SEM), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) presented that the drugs were incorporated into the spheres via weak interactions between the drugs and the polymeric chains, resulting in overall good drug stability. The cytotoxicity activity of the PVA spheres co-encapsulating both drugs was tested against the U2OS human osteosarcoma cell line by 3- (4,5-dimethylthiazol-2-yl) -2,5-diphenyltetrazolium bromide (MTT) assay, and compared to the spheres carrying either D14 or doxorubicin alone. The co-delivery showed a cytotoxic effect 2.6-fold greater than doxorubicin alone, revealing a significant synergistic effect with a coefficient of drug interaction (CDI) of 0.49. The obtained results suggest this developed PVA sphere as a potential dual-drug delivery system that could be used for the prominent synergistic anticancer activity of co-delivering D14 and doxorubicin, providing a new potential strategy for improved osteosarcoma treatment.