Development of a sorafenib-loaded solid self-nanoemulsifying drug delivery system: Formulation optimization and characterization of enhanced properties.

Sorafenib, marketed under the brand name Nexavar®, is a multiple tyrosine kinase inhibitor drug that has been actively used in the clinical setting for the treatment of several cancers. However, the low solubility and bioavailability of sorafenib constitute a significant barrier to achieving a good therapeutic outcome. We developed a sorafenib-loaded self-nanoemulsifying drug delivery system (SNEDDS) formulation composed of capmul MCM, tween 80, and tetraglycol, and demonstrated that the SNEDDS formulation could improve drug solubility with excellent self-emulsification ability. Moreover, the sorafenib-loaded SNEDDS exhibited anticancer activity against Hep3B and KB cells, which are the most commonly used hepatocellular carcinoma and oral cancer cell lines, respectively. Subsequently, to improve the storage stability and to increase the possibility of commercialization, a solid SNEDDS for sorafenib was further developed through the spray drying method using Aerosil® 200 and PVP K 30. X-ray diffraction and differential scanning calorimeter data showed that the crystallinity of the drug was markedly reduced, and the dissolution rate of the drug was further improved in formulation in simulated gastric and intestinal fluid conditions. In vivo study, the bioavailability of the orally administered formulation increases dramatically compared to the free drug. Our results highlight the use of the solid-SNEDDS formulation to enhance sorafenib's bioavailability and outlines potential translational directions for oral drug development.

pH-Sensitive Twin Liposomes Containing Quercetin and Laccase for Tumor Therapy.

In this study, functional twin liposomes (TLs) were designed by linking avidin-anchored single liposomes and biotin-anchored single liposomes via avidin-biotin interactions. Here, we first punched a hole on the liposome surface using the liposome magnetoporation method to prepare functional single liposomes, which were used for safely encapsulating quercetin (QER, as a model prodrug) or laccase (LAC, as a bioactive enzyme) inside the liposomes without the use of organic solvents; the pores were then plugged by pH-sensitive glycol chitosan grafted with 3-diethylaminopropylamine (GDEAP) and avidin (or biotin). As a result, single liposomes with QER and biotin-GDEAP were efficiently coupled with other liposomes with LAC and avidin-GDEAP. We demonstrated that the TLs could accelerate QER and LAC release at acidic pH (6.8), improving the LAC-mediated oxidization of QER and significantly elevating tumor cell death, suggesting that this strategy can be used as an efficient method for the programmed action of prodrugs.

Tumor-Targeting Liposomes with Transient Holes Allowing Intact Rituximab Internally.

In this study, the strategy of transient generation of holes in the liposome surface has been shown to enable safe encapsulation of a high-molecular weight antibody (rituximab, Mw ∼140 kDa) within liposomes. These transient holes generated using our magnetoporation method allowed rituximab to safely enter the liposomes, and then the holes were plugged using hyaluronic acid grafted with 3-diethylaminopropylamine (DEAP). In the tumor microenvironment, the resulting liposomal rituximab was destabilized because of the ionization of the DEAP moiety at the acidic pH 6.5, resulting in extensive release of rituximab. Consequently, the rituximab released from the liposomes accumulated at high levels in tumors and bound to the CD20 receptors overexpressed on Burkitt lymphoma Ramos cells. This event led to significant enhancement in tumor cell ablation through rituximab-mediated complement-dependent cytotoxicity and Bcl-2 signaling inhibition-induced cell apoptosis.

Preparation and Characterization of a Lutein Solid Dispersion to Improve Its Solubility and Stability.

Lutein has been used as a dietary supplement for the treatment of eye diseases, especially age-related macular degeneration. For oral formulations, we investigated lutein stability in artificial set-ups mimicking different physiological conditions and found that lutein was degraded over time under acidic conditions. To enhance the stability of lutein upon oral intake, we developed enteric-coated lutein solid dispersions (SD) by applying a polymer, hydroxypropyl methylcellulose acetate succinate (HPMCAS-LF), through a solvent-controlled precipitation method. The SD were characterized in crystallinity, morphology, and drug entrapment. In the dissolution profile of lutein SD, a F80 formulation showed resistance toward the acidic environment under simulated gastric conditions while exhibiting a bursting drug release under simulated intestinal conditions. Our results highlight the potential use of HPMCAS-LF as an effective matrix to enhance lutein bioavailability during oral delivery and to provide novel insights into the eye-care supplement industry, with direct benefits for the health of patients.

Cyclic RGD-Conjugated Hyaluronate Dot Bearing Cleavable Doxorubicin for Multivalent Tumor Targeting.

In this study, we developed an extremely small-sized water-soluble hyaluronate dot (dHA) conjugated with cyclic RGD (cRGD) and cleavable doxorubicin (DOX, as a model antitumor drug), named cRGD@dHA-c-DOX. This dot with HA moieties (as specific ligands to tumor CD44 receptors) and cRGD moieties (as specific ligands to tumor integrin αvß3) was designed to enable multivalent tumor targeting. In particular, the imine bonds, linking the DOX and dHA, can exhibit cleavage performance at endosomal pH, resulting in pH-triggered DOX release from cRGD@dHA-c-DOX. We demonstrated that cRGD@dHA-c-DOX resulted in highly improved cellular uptake and cell death in MDA-MB-231 tumor cells (CD44+, integrin αvß3+) compared to those in Huh7 tumor cells (CD44-, integrin αvß3-). In vivo studies using MDA-MB-231 tumor-bearing mice revealed that cRGD@dHA-c-DOX enhanced the tumor inhibition efficacy. These results suggest that cRGD@dHA-c-DOX can be utilized as a promising multivalent tumor-targeting drug carrier for highly efficient tumor treatment.

Revaprazan-loaded surface-modified solid dispersion: physicochemical characterization and in vivo evaluation.

The purpose of this research was to develop a novel revaprazan-loaded surface-modified solid dispersion (SMSD) with improved drug solubility and oral bioavailability. The impact of carriers on aqueous solubility of revaprazan was investigated. HPMC and Cremophor A25 were selected as an appropriate polymer and surfactant, respectively, due to their high drug solubility. Numerous SMSDs were prepared with various concentrations of carriers, using distilled water, and the drug solubility of each was assessed. Moreover, the physicochemical properties, dissolution and pharmacokinetics of selected SMSD in rats were assessed in comparison to revaprazan powder. Of the SMSDs assessed, the SMSD composed of revaprazan/HPMC/Cremophor A25 at the weight ratio of 1:0.28:1.12 had the most enhanced drug solubility (∼6000-fold). It was characterized by particles with a relatively rough surface, suggesting that the carriers were attached onto the surface of the unchanged crystalline revaprazan powder. It had a significantly higher dissolution rate, AUC and Cmax, and a faster Tmax value in comparison to revaprazan powder, with a 5.3-fold improvement in oral bioavailability of revaprazan. Therefore, from an environmental perspective, this SMSD system prepared with water, and without organic solvents, should be recommended as a revaprazan-loaded oral pharmaceutical alternative.

Novel revaprazan-loaded gelatin microsphere with enhanced drug solubility and oral bioavailability.

To develop a novel revaprazan-loaded gelatine microsphere with enhanced solubility and oral bioavailability, numerous gelatine microspheres were prepared using a spray-drying technique. The impact of gelatine amount on drug solubility in the gelatine microspheres was investigated. The physicochemical properties of the selected gelatine microsphere, such as shape, particle size and crystallinity, were evaluated. Moreover, its dissolution and pharmacokinetics in rats were assessed in comparison with revaprazan powder. Amongst the gelatine microspheres tested, the gelatine microsphere consisting of revaprazan and gelatine (1:2, w/w), which gave about 150-fold increased solubility, had the most enhanced drug solubility. It provided a spherical shape, amorphous drug and reduced particle size. Furthermore, it gave a higher dissolution rate and plasma concentration than did revaprazan powder. Particularly, it gave about 2.3-fold improved oral bioavailability in comparison with revaprazan powder. Therefore, this novel gelatine microsphere system is recommended as an oral pharmaceutical product of poorly water-soluble revaprazan.

Development of a novel celecoxib-loaded nanosuspension using a wet media milling process.

To develop a novel celecoxib (CXB)-loaded drug delivery system, numerous nanosuspensions were prepared with various polymers and surfactants using a wet media milling process, and their particle sizes were subsequently determined. A 24 full factorial design was used to identify the most appropriate preparation conditions. Pharmacokinetics of the selected nanosuspension were performed in rats and compared with those of a drug powder and a commercial CXB-loaded product. Among the carriers investigated, copovidone and sodium lauryl sulphate gave the smallest particle size of the drug in the nanosuspension. In particular, the nanosuspension prepared with 5% CXB, 4% copovidone, and 0.1% sodium lauryl sulphate, under the appropriate conditions, showed a particle size of approximately 190 nm, which was physically stable for at least 8 weeks. This nanosuspension provided a significantly higher plasma concentration and AUC in rats as compared with the drug powder and the commercial product. Thus, this novel CXB-loaded nanosuspension is a promising candidate with excellent stability and enhanced oral bioavailability.

Formulation of novel dry powder inhalation for fluticasone propionate and salmeterol xinafoate with capsule-based device.

The aim of this study was to develop a novel fluticasone propionate (FP) and salmeterol xinafoate (SX)-loaded dry powder inhaler (DPI) system, which was composed of powder formulation and performance. The air flow resistances were determined with various types of DPI device, showing that the modified RS01 device gave the specific resistance similar to the commercial DPI device. The particle properties of FP, SX, and inhalation grade lactose particles, such as particle size, size distribution, and fine content, were assessed. Subsequently, the aerodynamic behaviors of the DPI powder formulations were evaluated by the in vitro deposition of drugs in the DPI products using Andersen cascade impactor. Amongst the DPI powder formulations tested, the formulation composed of FP, SX, Respitose® SV003, Respitose® SV010, and Respitose® ML006 at the weight ratio of 0.5/0.145/19/19/2 gave depositions, emitted dose, fine particle dose, fine particle fraction, and mass median aerodynamic diameter of drugs similar to the commercial product, suggesting that they had similar aerodynamic behaviors. Furthermore, it gave excellent content uniformity. Thus, this DPI using the modified RS01 device would be recommended as a candidate for FP and SX-loaded pharmaceutical DPI products.

Development of a Physiologically Relevant Population Pharmacokinetic in Vitro-in Vivo Correlation Approach for Designing Extended-Release Oral Dosage Formulation.

Establishing a level A in vitro-in vivo correlation (IVIVC) for a drug with complex absorption kinetics is challenging. The objective of the present study was to develop an IVIVC approach based on population pharmacokinetic (POP-PK) modeling that incorporated physiologically relevant absorption kinetics. To prepare three extended release (ER) tablets of loxoprofen, three types of hydroxypropyl methylcellulose (HPMC 100, 4000, and 15000 cps) were used as drug release modifiers, while lactose and magnesium stearate were used as the diluent and lubricant, respectively. An in vitro dissolution test in various pH conditions showed that loxoprofen dissolution was faster at higher pH. The in vivo pharmacokinetics of loxoprofen was assessed following oral administration of the different loxoprofen formulations to Beagle dogs (n = 22 in total). Secondary peaks or shoulders were observed in many of the individual plasma concentration vs time profiles after ER tablet administration, which may result from secondary absorption in the intestine due to a dissolution rate increase under intestinal pH compared to that observed at stomach pH. In addition, in vivo oral bioavailability was found to decrease with prolonged drug dissolution, indicating site-specific absorption. Based on the in vitro dissolution and in vivo absorption data, a POP-PK IVIVC model was developed using S-ADAPT software. pH-dependent biphasic dissolution kinetics, described using modified Michaelis-Menten kinetics with varying Vmax, and site-specific absorption, modeled using a changeable absorbed fraction parameter, were applied to the POP-PK IVIVC model. To experimentally determine the biphasic dissolution profiles of the ER tablets, another in vitro dissolution test was conducted by switching dissolution medium pH based on an in vivo estimate of gastric emptying time. The model estimated, using linear regression, that in vivo initial maximum dissolution rate (Vmax(0)in vivo) was highly correlated (r2 > 0.998) with in vitro (Vmax(0)in vitro), indicating that in vivo dissolution profiles obtained from POP-PK modeling could be converted to in vitro dissolution profiles and vice versa. Monte Carlo simulations were performed for model validation, and prediction errors for Cmax and AUC were all within the acceptable range (90 to 110%) according to the FDA guidelines. The developed model was successfully applied for the prediction of in vivo pharmacokinetics of a loxoprofen double-layered tablet using the in vitro dissolution profile. In conclusion, a level A IVIVC approach was developed and validated using population modeling that accounted for pH-dependent dissolution and site-specific absorption. Excellent correlations were observed between in vitro and in vivo dissolution profiles. This new approach holds great promise for the establishment of IVIVCs for drug and formulation development where absorption kinetics strongly depend on complex physiologically absorption processes.

Therapeutic advantage of inhaled tacrolimus-bound albumin nanoparticles in a bleomycin-induced pulmonary fibrosis mouse model.

Tacrolimus (Tac) is an immunosuppressant that inhibits translocation of nuclear factor of activated T cells and has therapeutic potential for pulmonary fibrosis. Here, we investigated the therapeutic efficacy of a sustained-release type inhaled Tac formulation for treating bleomycin-induced pulmonary fibrosis. Inhalation has many meaningful advantages over injections, such as improved patient compliance, safety, and therapeutic effect. To this end, we fabricated inhalable albumin nanoparticles with bound Tac (Tac Alb-NPs) at a daily therapeutic dose (60 µg/mouse) using a high-pressure homogenizer via nanoparticle albumin-bound technology. The Tac Alb-NPs were spherical, ∼ 182.1 ± 28.5 nm in size, with a zeta potential of -34.5 ± 0.3 mV, and the Tac incorporation efficiency was as high as ∼ 85.3%. The bound tacrolimus was released gradually from Tac Alb-NPs for ∼ 24 h, which was sufficient time for pulmonary delivery. Most of all, the inhaled Tac Alb-NPs displayed remarkable anti-fibrotic efficacy in mice with bleomycin-induced pulmonary fibrosis, which was much better than the efficacy resulting from intraperitoneal administration of Tac (60 µg/mouse) based on histopathological results (hematoxylin and eosin and Masson's trichrome staining). Furthermore, the inhaled Cy5.5-labelled Tac Alb-NPs were visualized throughout the lungs of mice for ∼ 48 h, indicating direct exposure to fibrotic tissues in lung lesions. In conclusion, Tac Alb-NPs offer great potential as an inhalation delivery formulation for treating pulmonary fibrosis. Additionally, these NPs would be particularly useful as an effective and safe prototype for delivering practically insoluble therapeutic agents into the lungs.

Folate-Mediated Targeted Delivery of Combination Chemotherapeutics Loaded Reduced Graphene Oxide for Synergistic Chemo-Photothermal Therapy of Cancers.

PURPOSE: Larger surface area for drug incorporation and superior optical activity makes reduced graphene oxide (rGO) a suitable drug carrier for combination chemotherapeutics delivery. And folate receptors are potential mediators for cancer targeted delivery. This study mainly aimed to prepare irinotecan (IRI)- and docetaxel (DOC)-loaded, folate (FA)-conjugated rGO (FA-P407-rGO/ID) for synergistic cancer therapy. METHODS: FA-P407-rGO/ID was prepared as aqueous dispersion. Characterization was performed using high performance liquid chromatography (HPLC), transmission electron microscopy (TEM), atomic force microscopy (AFM), ultraviolet/visible spectroscopy, fourier transform infrared spectroscopy (FTIR) and drug release. In vitro cellular studies were performed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS), fluorescence-activated cell sorting (FACS) and western blot analyses. RESULTS: Our results revealed successful preparation of stable FA-P407-rGO/ID formulation with enhanced drug release profiles in acidic microenvironment. In vitro cytotoxicity of the formulation on folate receptor-expressing human mammary carcinoma (MCF-7) cells was higher than that when free IRI/DOC combination (ID) was used; such increased cytotoxicity was not observed in folate receptor-negative hepatocellular carcinoma (HepG2) cells. Cellular uptake of FA-P407-rGO/ID in MCF-7 cells was higher than in HepG2 cells. Further, FACS and western blot analysis revealed better apoptotic effects of the formulation in MCF-7 cells than in HepG2 cells, suggesting the important role of folate receptors for targeted chemotherapy delivery to cancer cells. Near infrared irradiation further enhanced the apoptotic effect in cancer cells, resulting from the photothermal effects of rGO. CONCLUSIONS: Hence, FA-P407-rGO/ID can be considered as a potential formulation for folate-targeted chemo-photothermal therapy in cancer cells.

Doxorubicin-Bound Albumin Nanoparticles Containing a TRAIL Protein for Targeted Treatment of Colon Cancer.

PURPOSE: We developed a new nanoparticle formulation comprised of human serum albumin (HSA) for co-delivery of doxorubicin (Dox) and tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) with the goal of apoptotic synergy in the treatment of colon cancer. METHODS: TRAIL (0.2, 0.4, 1.0%)- and Dox-loaded HSA nanoparticles (TRAIL/Dox HSA NPs) were prepared by using the nab(TM) technology. Morphological and physicochemical characterizations were investigated by dynamic light scattering and transmission electron microscopy. Synergistic cytotoxicity, apoptotic activity, and potential penetration into mass tumor were determined in HCT116 cell-based systems. Furthermore, antitumor efficacy and tumor targeting were also investigated. RESULTS: TRAIL/Dox HSA NPs were uniformly spherical with sizes of 60 ~ 120 nm. The encapsulation efficacy of Dox and TRAIL was 68.9-77.2% and 80.4-86.0%, respectively. TRAIL 1.0%/Dox HSA NPs displayed the best inhibition of HCT116 colon cancer cells; inhibition was 6 times higher than achieved with Dox HSA NPs. The TRAIL 1.0%/Dox HSA NPs formulation was studied further. Flow cytometry analysis and TUNEL assay revealed that TRAIL 1.0%/Dox HSA NPs had markedly greater apoptotic activity than Dox HSA NPs. In HCT116 tumor-bearing BALB/c nu/nu mice, TRAIL 1.0%/Dox HSA NPs had significantly higher antitumor efficacy than Dox HSA NPs (tumor volume; 933.4 mm(3) vs. 3183.7 mm(3), respectively). TRAIL 1.0%/Dox HSA NPs penetrated deeply into tumor masses in a HCT116 spheroid model and localized in tumor sites after tail vein injection. CONCLUSIONS: Data indicate that TRAIL 1.0%/Dox HSA NPs offer advantages of co-delivery of Dox and TRAIL in tumors, with potential synergistic apoptosis-based anticancer therapy.

Influence of polyvinylpyrrolidone quantity on the solubility, crystallinity and oral bioavailability of fenofibrate in solvent-evaporated microspheres.

The objective of this study is to explore the influence of polyvinylpyrrolidone (PVP) quantity on the solubility, crystallinity and oral bioavailability of poorly water-soluble fenofibrate in solvent-evaporated microspheres. Numerous microspheres were prepared with fenofibrate, sodium lauryl sulphate (SLS) and PVP using the spray-drying technique. Their aqueous solubility, dissolution, physicochemical properties and pharmacokinetics in rats were assessed. The drug in the solvent-evaporated microspheres composed of fenofibrate, PVP and SLS at the weight ratio of 1:0.5:0.25 was not entirely changed to the amorphous form and partially in the microcrystalline state. However, the microspheres at the weight ratio of 1:4:0.25 provided the entire conversion to the amorphous form. The latter microspheres, with an improvement of about 115 000-fold in aqueous solubility and 5.6-fold improvement in oral bioavailability compared with the drug powder, gave higher aqueous solubility and oral bioavailability compared with the former. Thus, PVP quantity played an important role in these properties of fenofibrate in the solvent-evaporated microspheres.

Novel piroxicam-loaded nanospheres generated by the electrospraying technique: physicochemical characterisation and oral bioavailability evaluation.

To determine if a novel electrospraying technique could be applied to an oral drug delivery system for improving the solubility and oral bioavailability of poorly water-soluble piroxicam; the nanospheres were generated with drug and polyvinylpyrrolidone (PVP) using electrospraying technique; and their physicochemical properties, solubility, release and pharmacokinetics were evaluated in comparison with piroxicam powder. All nanospheres had significantly increased drug solubility and dissolution rates in comparison with the drug powder. In particular, the nanosphere composed of piroxicam and PVP at a weight ratio of 2:8 gave about 600-fold higher solubility, 15-fold higher release rate and 3-fold higher AUC in comparison to piroxicam powder, leading to significantly enhanced oral bioavailability in rats, due to the mingled effect of nanonisation along with transformation to the amorphous state. Thus, this electrospraying technique can be utilised to produce a novel oral nanosphere delivery system with enhanced solubility and oral bioavailability for poorly water-soluble piroxicam.

Human serum albumin-TRAIL conjugate for the treatment of rheumatoid arthritis.

Albumin conjugation is viewed as an effective means of protracting short in vivo lifespans of proteins and targeting rheumatoid arthritis (RA). In this study, we present a human serum albumin (HSA) conjugate linked with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) via a bifunctional PEG derivative (HSA-TRAIL). Prepared HSA-TRAIL was found to have a larger molecular size (∼240 kDa, 15.4 nm) than TRAIL (∼66 kDa, 6.2 nm), and its bioactivity (apoptosis, cytotoxicity, and antiproliferation) was well preserved in Mia Paca-2 cells and mouse splenocytes. The enhanced therapeutic efficacy of HSA-TRAIL was demonstrated in collagen-induced arthritis (CIA) mice. The incidence and clinical scores, expressed as degree of erythema and swelling in HSA-TRAIL-treated mice, were remarkably lower than those of TRAIL-treated mice. The serum levels of pro-inflammatory cytokines IFN-γ, TNF-α, IL-1ß, and IL-2 in HSA-TRAIL-treated mice were significantly lower than those of TRAIL-treated mice. Furthermore, HSA-TRAIL accumulated in the hind paws of CIA mice, not in naïve TRAIL mice. Pharmacokinetic profiles of HSA-TRAIL were greatly improved in comparison to those of TRAIL (AUCinf: 844.1 ± 130.0 vs 36.0 ± 1.2 ng·h/mL; t1/2: 6.20 ± 0.72 vs 0.23 ± 0.01 h, respectively). The HSA-TRAIL conjugate, which presents clear advantages of targeting RA and long systemic circulation by HSA and unique anti-inflammatory efficacy by TRAIL, has potential as a novel treatment for rheumatoid arthritis.

Alveolar macrophage phagocytosis-evading inhaled microgels incorporating nintedanib-PLGA nanoparticles and pirfenidone-liposomes for improved treatment of pulmonary fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a chronic inflammatory and fibrotic response-driven lung disease that is difficult to cure because it manifests excessive profibrotic cytokines (e.g., TGF-ß), activated myofibroblasts, and accumulated extracellular matrix (ECM). In an attempt to develop an inhalation formulation with enhanced antifibrotic efficacy, we sought to fabricate unique aerosolizable inhaled microgels (µGel) that contain nintedanib-poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs; n-PN) and pirfenidone-liposomes (p-LP). The aero-µGel was ∼12 µm, resisted phagocytosis by alveolar macrophages in vitro and in vivo, and protected inner-entrapped n-PN and p-LP. The n-PN/p-LP@aero-µGel caused enhanced/extended antifibrotic efficacy in a bleomycin-induced pulmonary fibrosis mouse presumably due to prolonged lung residence. Consequently, the results obtained by intratracheal aerosol insufflation of our n-PN/p-LP@aero-µGel twice a week were much better than those by as many as seven doses of single or mixed applications of n-PN or p-LP. The antifibrotic/pharmacokinetic results for the n-PN/p-LP@aero-µGel included reduced fibrosis progression, restored lung physiological functions, deactivated myofibroblasts, inhibited TGF-ß progression, and suppressed ECM component production (collagen I and α-SMA) along with prolonged lung retention time. We believe that our n-PN/p-LP@aero-µGel increased the local availability of both nintedanib and pirfenidone due to evasion of alveolar macrophage phagocytosis and prolonged lung retention with reduced systemic distribution. Through this approach, our inhalation formulation subsequently attenuated fibrosis progression and improved lung function. Importantly, these results hold profound implications in the therapeutic potential of our n-PN/p-LP@aero-µGel to serve as a clinically promising platform, providing significant advancements for improved treatment of many respiratory diseases including IFP.

Fabrication of stem cell heterospheroids with sustained-release chitosan and poly(lactic-co-glycolic acid) microspheres to guide cell fate toward chondrogenic differentiation.

Mesenchymal stem cell (MSC)-based therapies show great potential in treating various diseases. However, control of the fate of injected cells needs to be improved. In this work, we developed an efficient methodology for modulating chondrogenic differentiation of MSCs. We fabricated heterospheroids with two sustained-release depots, a quaternized chitosan microsphere (QCS-MP) and a poly (lactic-co-glycolic acid) microsphere (PLGA-MP). The results show that heterospheroids composed of 1 × 104 to 5 × 104 MSCs formed rapidly during incubation in methylcellulose medium and maintained high cell viability in long-term culture. The MPs were uniformly distributed in the heterospheroids, as shown by confocal laser scanning microscopy. Incorporation of transforming growth factor beta 3 into QCS-MPs and of dexamethasone into PLGA-MPs significantly promoted the expression of chondrogenic genes and high accumulation of glycosaminoglycan in heterospheroids. Changes in crucial metabolites in the dual drug depot-engineered heterospheroids were also evaluated using 1H NMR-based metabolomics analysis to verify their successful chondrogenic differentiation. Our heterospheroid fabrication platform could be used in tissue engineering to study the effects of various therapeutic agents on stem cell fate.

Amplified Fenton-Based Oxidative Stress Utilizing Ultraviolet Upconversion Luminescence-Fueled Nanoreactors for Apoptosis-Strengthened Ferroptosis Anticancer Therapy.

As an emerging anticancer strategy, ferroptosis has recently been developed in combination with current therapeutic modalities to overcome the existing limitations of conventional therapies. Herein, an ultraviolet (UV) upconversion luminescence-fueled nanoreactor is explored to combine ferroptosis and apoptosis through the UV-catalyzed Fenton reaction of an iron supplement (ferric ammonium citrate) loaded in a mesoporous silica layer in addition to the support of a chemotherapeutic agent (cisplatin) attached on the functionalized silica surface for the treatment of triple negative breast cancer (TNBC). The nanoplatform can circumvent the low penetration depth typical of UV light by upconverting near-infrared irradiation and emitting UV photons that convert Fe3+ to Fe2+ to boost the generation of hydroxyl radicals (·OH), causing devastating lipid peroxidation. Apart from DNA damage-induced apoptosis, cisplatin can also catalyze Fenton-based therapy by its abundant production of hydrogen peroxide (H2O2). As a bioinspired lipid membrane, the folate receptor-targeted liposome as the coating layer offers high biocompatibility and colloidal stability for the upconversion nanoparticles, in addition to prevention of the premature release of encapsulated hydrophilic compounds, before driving the nanoformulation to the target tumor site. As a result, superior antitumor efficacy has been observed in a 4T1 tumor-bearing mouse model with negligible side effects, suggesting that such a nanoformulation could play a pivotal role in effective apoptosis-strengthened ferroptosis TNBC therapy.

Development and characterization of pH-responsive nanocarriers for chemo-photothermal combination therapy of acidic tumors.

The combination of photothermal therapy and chemotherapy has been considered a promising strategy for improving the excellent antitumor activities of these treatments. In this study, we developed a new simple type of pH-sensitive chemo-photothermal combination agent capable of repeated exposures to a near-infrared (NIR) laser and evaluated its anticancer efficacy in vitro and in vivo. Doxorubicin (Dox) and gold nanoclusters (GNCs) were successfully co-loaded into pH-sensitive nanoparticles (poly(ethylene glycol)-poly[(benzyl-l-aspartate)-co-(N-(3-aminopropyl)imidazole-L-aspartamide)] (PEG-PABI)), resulting in a particle size of approximately120 nm with a narrow size distribution. The dual drug-loaded nanoparticles (Dox/GNC-loaded PEG-PABI micelles (Dox/GNC-Ms)) showed consistent pH-sensitive properties and heat generation efficiency after repeated NIR laser exposure. In particular, GNC-M has improved photothermal stability while maintaining high photothermal conversion efficiency, addressing the shortcomings of previous gold nanoparticles. As the concentration of GNC-Ms, irradiation light exposure time, and light source intensity increased, the amount of heat generated and the anticancer effect increased. When Dox was encapsulated with GNCs (Dox/GNC-Ms), a faster drug release rate under acidic pH conditions and a strong synergistic effect against U87MG cells were observed. When the Dox/GNC-M system was extended to in vivo studies, it effectively increased the temperature of the tumor tissue under near-infrared irradiation and showed excellent anticancer efficacy. Therefore, the Dox/GNC-M system could be a simple but promising strategy for chemo-photothermal combination treatment capable of targeting acidic tumors.