Magnetic Targeting and Ultrasound Activation of Liposome-Microbubble Conjugate for Enhanced Delivery of Anticancer Therapies.

Effective delivery of chemotherapeutics with minimal toxicity and maximal outcome is clinically important but technically challenging. Here, we synthesize a complex of doxorubicin (DOX)-loaded magneto-liposome (DOX-ML) microbubbles (DOX-ML-MBs) for magnetically responsive and ultrasonically sensitive delivery of anticancer therapies with enhanced efficiency. Citrate-stabilized iron oxide nanoparticles (MNs) of 6.8 ± 1.36 nm were synthesized, loaded with DOX in the core of oligolamellar vesicles of 172 ± 9.2 nm, and covalently conjugated with perfluorocarbon (PFC)-gas-loaded microbubbles to form DOX-ML-MBs of ∼4 µm. DOX-ML-MBs exhibited significant magnetism and were able to release chemotherapeutics and DOX-MLs instantly upon exposure to ultrasound (US) pulses. In vitro studies showed that DOX-ML-MBs in the presence of US pulses promoted apoptosis and were highly effective in killing both BxPc-3 and Panc02 pancreatic cancer cells even at a low dose. Significant reduction in the tumor volume was observed after intravenous administration of DOX-ML-MBs in comparison to the control group in a pancreatic cancer xenograft model of nude mice. Deeply penetrated iron oxide nanoparticles throughout the magnetically targeted tumor tissues in the presence of US stimulation were clearly observed. Our study demonstrated the potential of using DOX-ML-MBs for site-specific targeting and controlled drug release. It opens a new avenue for the treatment of pancreatic cancer and other tissue malignancies where precise delivery of therapeutics is necessary.

Ultrathin MoS2 nanosheets for high-performance photoelectrochemical applications via plasmonic coupling with Au nanocrystals.

In this work, we prepared ultrathin MoS2 nanosheets with exposed active edge sites and high electric conductivity that can sufficiently absorb light in the visible region to enable solar energy conversion. The gold nanocrystal-decorated MoS2 nanosheets facilitate sufficiently enhanced photoelectrochemical water splitting in the UV-visible region. Different Au nanostructures, such as Au nanoparticles and nanorods, were modified on the surface of MoS2 nanosheets to promote photoelectrochemical water decomposition. By spin-coating a synthetic gold-modified MoS2 hybrid photoanode on a FTO substrate, the efficiency of photoelectrochemical water oxidation was significantly enhanced, by 2 times (nanorods) and 3.5 times (nanoparticles) in the visible-infrared region; furthermore, the average optical resistance was reduced by a factor of two compared to the MoS2 photoanode without Au, and the photocurrent increases exponentially when the system bias was greater than 0.7 volts. The Au-MoS2 metal-semiconductor interface plays an important role in studying the surface plasmon interactions, charge transfer mechanism, and electric field amplification. This rational design for such a unique hybrid nanostructure explains the plasmon-enhanced photoelectrochemical water splitting. This current contribution provides a new path for using the plasmonic metal/semiconductor heterostructure to effectively harvest UV-visible light for solar fuel generation.

Sustained release paclitaxel-loaded core-shell-structured solid lipid microparticles for intraperitoneal chemotherapy of ovarian cancer.

The current clinical paradigm for ovarian cancer treatment has a poor prognosis, partially due to the efficacy and toxicity concerns associated with the available chemotherapeutic formulations. To overcome these limitations, we have designed core-shell-structured paclitaxel (PTX) laden solid lipid microparticles (PTX-SLMPs) for intraperitoneal treatment of ovarian cancer. A single-step coaxial electro hydrodynamic atomization (CEHDA) process has been explored to synthesize core-shell structure of PTX-SLMPs with the particle size of 1.76 ± 0.37 µm. Core-shell PTX-SLMPs have high encapsulation efficiency of 94.73% with sustained drug release profile. In vitro evaluation of PTX-SLMPs in SKOV-3 ovarian cancer cells yield significant enhancement in cytotoxicity when compared with Taxol®. In vivo pharmacokinetic study demonstrated slower absorption of PTX into the systemic circulation after intraperitoneal (i.p.) administration of PTX-SLMPs in Wistar rats implying the PTX-SLMPs remained in the peritoneal cavity and released the PTX for prolonged period of time. Through these studies, we have demonstrated the technical potential of core-shell structured PTX-SLMPs, which can enhance passive targeting of PTX to the tumor in the treatment of not only ovarian cancer but also in other peritoneal cancer.

Core-shell microencapsulation of curcumin in PLGA microparticles: programmed for application in ovarian cancer therapy.

In our study, we have established a novel liquid-driven co-flow focusing (LDCF) process to fabricate curcumin (CUR)-loaded poly (lactic-co-glycolic acid) (PLGA) microparticles (CPMs). LDCF-CPMs of size 20.26 ± 2.37 µm have high encapsulation efficiency (>70%) and were intended for application in ovarian cancer by intraperitoneal (IP) administration. LDCF-CPMs have smooth surface with narrow size distribution and a core-shell structured verified by confocal microscopy which can be precisely controlled by changing the flow rates of focusing, outer and inner phases. The LDCF-CPMs reveal the physiochemical stability with sustained release profile corresponding to 95% CUR release over a period of 14 days in an in vitro release medium. Moreover, LDCF-CPMs were testified for cytotoxicity against SKOV-3 ovarian cancer cell lines and peritoneal delivery advantages by animal experiments. The pharmacokinetics of LDCF-CPMs in rats following IP injection shows slow systemic absorption with mean residence time (MRT) of 13.54 h in comparison with 9.82 and 6.74 h for SE-CPMs and free CUR, respectively. In addition, IP delivery of CUR can expose the ovarian tumour to higher concentration for a longer duration by programming the thickness of the shell. The study provides compelling evidence for LDCF-CPMs having high therapeutic opportunity in the treatment of peritoneal cancers, such as ovarian, that reside in the peritoneal cavity.

Characteristics of Artemether-Loaded Poly(lactic-co-glycolic) Acid Microparticles Fabricated by Coaxial Electrospray: Validation of Enhanced Encapsulation Efficiency and Bioavailability.

Artemether is one of the most effective drugs for the treatment of chloroquine-resistant and Plasmodium falciparum strains of malaria. However, its therapeutic potency is hindered by its poor bioavailability. To overcome this limitation, we have encapsulated artemether in poly(lactic-co-glycolic) acid (PLGA) core-shell microparticles (MPs) using the coaxial electrospray method. With optimized process parameters including liquid flow rates and applied electric voltages, experiments are systematically carried out to generate a stable cone-jet mode to produce artemether-loaded PLGA-MPs with an average size of 2 µm, an encapsulation efficiency of 78 ± 5.6%, and a loading efficiency of 11.7%. The in vitro release study demonstrates the sustained release of artemether from the core-shell structure in comparison with that of plain artemether and that of MPs produced by single-axial electrospray without any relevant cytotoxicity. The in vivo studies are performed to evaluate the pharmacokinetic characteristics of the artemether-loaded PLGA-MPs. Our study implies that artemether can be effectively encapsulated in a protective shell of PLGA for controlled release kinetics and enhanced oral bioavailability.