The in vitro and in vivo anti-tumor effects of MTX-Fe3O4-PLLA-PEG-PLLA microspheres prepared by suspension-enhanced dispersion by supercritical CO2

Supercritical fluid technology for the development of innovative ophthalmic medical devices: Drug loaded intraocular lenses to mitigate posterior capsule opacification

Supercritical impregnation technology was applied to load acrylic intraocular lenses (IOLs) with methotrexate to produce a sustained drug delivery device to mitigate posterior capsule opacification. Drug release kinetics were studied in vitro and used to determine the drug loading. Loaded IOLs and control IOLs treated under the same operating conditions, but without drug, were implanted ex vivo in human donor capsular bags. The typical cell growth was observed and immunofluorescence staining of three common fibrosis markers, fibronectin, F-actin and α-smooth muscle actin was carried out. Transparent IOLs presenting a sustained release of methotrexate for more than 80 days were produced. Drug loading varying between 0.43 and 0.75 ± 0.03 µg_drug·mg^-1_IOL were obtained when varying the supercritical impregnation pressure (8 and 25 MPa) and duration (30 and 240 min) at 308 K. The use of ethanol (5 mol%) as a co-solvent did not influence the impregnation efficiency and was even unfavorable at certain conditions. Even if the implantation of methotrexate loaded IOLs did not lead to a statistically significant variation in the duration required for a full cell coverage of the posterior capsule in the human capsular bag model, it was shown to reduce fibrosis by inhibiting epithelial-mesenchymal transformation. The innovative application presented has the potential to gain clinical relevance.

Supercritical Fluid Technology: An Emphasis on Drug Delivery and Related Biomedical Applications

During the past few decades, supercritical fluid (SCF) has emerged as an effective alternative for many traditional pharmaceutical manufacturing processes. Operating active pharmaceutical ingredients (APIs) alone or in combination with various biodegradable polymeric carriers in high-pressure conditions provides enhanced features with respect to their physical properties such as bioavailability enhancement, is of relevance to the application of SCF in the pharmaceutical industry. Herein, recent advances in drug delivery systems manufactured using the SCF technology are reviewed. We provide a brief description of the history, principle, and various preparation methods involved in the SCF technology. Next, we aim to give a brief overview, which provides an emphasis and discussion of recent reports using supercritical carbon dioxide (SC-CO2 ) for fabrication of polymeric carriers, for applications in areas related to drug delivery, tissue engineering, bio-imaging, and other biomedical applications. We finally summarize with perspectives.

Preparation and antitumor effect evaluation of composite microparticles co-loaded with siRNA and paclitaxel by a supercritical process

The co-delivery of siRNA and therapeutic agents provides an effective method for cancer chemotherapy by avoiding drug resistance during the treatment. With a combination of ionic gelation and supercritical fluid technology, nanoparticle-embedded composite microparticles (CMPs) co-loaded with siRNA and paclitaxel (siRNA-PTX-CMPs) were successfully prepared. The results show that CMPs embedded with nanoparticles with a diameter of 50-100 nm exhibited a spherical shape and core-shell structure with a mean diameter of 323 nm. The encapsulation efficiency of siRNA in chitosan nanoparticles (CS NPs) was 96.97%. The drug load and encapsulation efficiency of PTX-loaded CMPs (5% dosage) were 1.40% and 27.95%, respectively; both these increased with an increase in dosage. It was found that no change had occurred in the functional groups of the components during the supercritical process, while the physical form of PTX had shifted to an amorphous state. In the cell experiments, the CMPs clustered around the nucleus after being taken up by the Bcap-37 cells. The results of the antitumor effect experiments revealed that the co-loaded siRNA-PTX-CMPs achieved a significantly better synergistic effect than single dosages, which indicated that the co-delivery system developed by the supercritical process could have potential in the application of cancer chemotherapy.