Porous silicon oxide–PLGA composite microspheres for sustained ocular delivery of daunorubicin

Abstract

A water-soluble anthracycline antibiotic drug (daunorubicin, DNR) was loaded into oxidized porous silicon (pSiO2) microparticles and then encapsulated with a layer of polymer (poly lactide-co-glycolide, PLGA) to investigate their synergistic effects in control of DNR release. Similarly fabricated PLGA-DNR microspheres without pSiO2, and pSiO2 microparticles without PLGA were used as control particles. The composite microparticles synthesized by a solid-in-oil-in-water (S/O/W) emulsion method have mean diameters of 52.33±16.37 μm for PLGA-pSiO2_21/40-DNR and the mean diameter of 49.31±8.87 μm for PLGA-pSiO2_6/20-DNR. The mean size, 26.00±8 μm, of PLGA-DNR was significantly smaller, compared with the other two (p<0.0001). Optical microscopy revealed that PLGA-pSiO2-DNR microsphere contained multiple pSiO2 particles. In vitro release experiments determined that control PLGA-DNR microspheres completely released DNR within 38 days and control pSiO2-DNR microparticles (with no PLGA coating) released DNR within 14 days, while the PLGA-pSiO2-DNR microspheres released DNR for 74 days. Temporal release profiles of DNR from PLGA-pSiO2 composite particles indicated that both PLGA and pSiO2 contribute to the sustained release of the payload. The PLGA-pSiO2 composite displayed a more constant rate of DNR release than the pSiO2 control formulation, and it displayed a significantly slower release of DNR than either the PLGA or pSiO2 formulations. We conclude that this system may be useful in managing unwanted ocular proliferation when formulated with anti-proliferation compounds such as DNR.

Luminescent Silicon Diatom Replicas: Self‐Reporting and Degradable Drug Carriers with Biologically Derived Shape for Sustained Delivery of Therapeutics

“…The higher drug loading capacity of silica diatoms could be due to hydrogen bonding between the primary amine of DNR and hydroxyl groups present on the surface of diatom silica. However, this amount of drug loading in silicon diatoms is comparable or slightly higher than that achieved through physical adsorption onto silicon and silica porous nanoparticles reported in previous studies …”

The potential use of novel chitosan-coated deformable liposomes in an ocular drug delivery system

“…To overcome the disadvantages of traditional eye drops, several ocular drug delivery systems have been developed in recent years, such as in-situ gels [4], microemulsions [5], microspheres [6], liposomes [7], solid lipid nanoparticles (SLN) [8], and nanostructured lipid carriers (NLC) [9]. Among them, liposomes have a great potential for penetration enhancement and high biocompatibility [10,11] .…”

Silicon Nanostructures for Cancer Diagnosis and Therapy

“…During the past decades, pSi has been widely used in orthopedic purpose and biomedical applications [17,[61][62][63], especially utilized as high-performance carriers for delivery of therapeutic agents to take advantages of their attractive properties, including large surface-to-volume ratio, excellent biocompatibility and biodegradability, and high loading efficiency, and so on. Since the early study of using pSi as carriers for insulin delivery [64], pSi has received great attention in drug delivery systems for loading conventional drugs (e.g., daunorubicin, indomethacin [IMC], methotrexate [MTX], sorafenib, DOX, atorvastatin and celecoxib, among others), genes (e.g., siRNA) and proteins (e.g., peptide, insulin, among others) [8,30,31,[65][66][67][68][69][70][71][72][73][74][75][76][77][78][79]. As far as 2006, Vaccari and coworkers loaded DOX molecules into pSi materials to treat human colon adenocarcinoma cancer cells [68].…”