Double Emulsion Solvent Evaporation Method Research Articles

PLGA encapsulated γ-cyclodextrin-meropenem inclusion complex formulation for oral delivery

Meropenem (MER) is one of the last resort antibiotics used to treat resistant bacterial infections. However, the clinical effectiveness of MER is hindered due to chemical instability in aqueous solution and gastric pH, and short plasma half-life. Herein, a novel multi-material delivery system based on γ-cyclodextrin (γ-CD) and poly lactic-co-glycolic acid (PLGA) is demonstrated to overcome these challenges. MER showed a saturated solubility of 14 mg/100 mL in liquid CO2 and later it was loaded into γ-CD to form the inclusion complex using the liquid CO2 method. The γ-CD and MER inclusion complex (MER-γ-CD) was encapsulated into PLGA by the well-established double emulsion solvent evaporation method. The formation of the inclusion complex was confirmed using FTIR, XRD, DSC, SEM, and 1H NMR and docking study. Further, MER-γ-CD loaded PLGA nanoparticles (MER-γ-CD NPs) were characterized by SEM, DLS, and FTIR. The drug loading and entrapment efficiency for MER-γ-CD were 21.9 and 92. 2% w/w, respectively. However, drug loading and entrapment efficiency of MER-γ-CD NPs was significantly lower at up to 3.6 and 42.1% w/w, respectively. In vitro release study showed that 23.6 and 27.4% of active (non-degraded drug) and total drug (both degraded and non-degraded drug) were released from MER-γ-CD NPs in 8 h, respectively. The apparent permeability coefficient (Papp) (A to B) for MER, MER-γ-CD, and MER-γ-CD NPs were 2.63 × 10−6 cm/s, 2.81 × 10−6 cm/s, and 2.92 × 10−6 cm/s, respectively. For secretory transport, the Papp (B to A) were 1.47 × 10−6 cm/s, 1.53 × 10−6 cm/s, and 1.58 × 10−6 cm/s for MER, MER-γ-CD and MER-γ-CD NPs, respectively. Finally, the MER-γ-CD inclusion complex and MER-γ-CD NPs retained MER’s antibacterial activities against Staphylococcus aureus and Pseudomonas aeruginosa. Overall, this work demonstrates the significance of MER-γ-CD NPs to protect MER from gastric pH with controlled drug release, while retaining MER’s antibacterial activity.

Preparation, Characterization, Pharmacokinetic, and Therapeutic Potential of Novel 6-Mercaptopurine-Loaded Oral Nanomedicines for Acute Lymphoblastic Leukemia.

BackgroundAcute lymphoblastic leukemia (ALL) is the most common hematologic malignancy in children. It requires a long and rigorous course of chemotherapy treatments. 6-Mercaptopurine (6-MP) is one of the primary drugs used in chemotherapy. Unfortunately, its efficacy has been limited due to its insolubility, poor bioavailability and serious adverse effects. To overcome these drawbacks, we constructed 6-mercaptopurine (6-MP)-loaded nanomedicines (6-MPNs) with biodegradable poly(lactide-co-glycolide) (PLGA) to enhance the anticancer efficacy of 6-MP.MethodsWe prepared the 6-MPNs using a double-emulsion solvent evaporation method, characterizing them for the physicochemical properties. We then investigated the plasma, intestinal region and other organs in Sprague Dawley (SD) rats for pharmacokinetics. Additionally, we evaluated its anticancer efficacy in vitro on the human T leukemia cell line Jurkat and in vivo on the ALL model mice.ResultsThe 6-MPNs were spherical in shape with uniform particle size and high encapsulation efficiency. The in vitro release profile showed that 6-MPNs exhibited a burst release that a sustained release phase then followed. The apoptosis assay demonstrated that 6-MPNs could improve the in vitro cytotoxicity in Jurkat cells. Pharmacokinetics profiles revealed that 6-MPNs had improved oral bioavailability. Tissue distribution experiments indicated that 6-MPNs increased the duodenum absorption of 6-MP, at the same time having a low accumulation of the toxic metabolites of 6-MP. The in vivo pharmacodynamics study revealed that 6-MPNs could prolong the survival time of the ALL model mice. The prepared 6-MPNs, therefore, have superior properties in terms of anticancer efficacy against ALL with reduced systemic toxicity.ConclusionOur nanomedicines provide a promising delivery strategy for 6-MP; they offer a simple preparation method and high significance for clinical translation.

An Injectable Nano-Enabled Thermogel to Attain Controlled Delivery of p11 Peptide for the Potential Treatment of Ocular Angiogenic Disorders of the Posterior Segment.

This investigation focused on the design of an injectable nano-enabled thermogel (nano-thermogel) system to attain controlled delivery of p11 anti-angiogenic peptide for proposed effective prevention of neovascularisation and to overcome the drawbacks of the existing treatment approaches for ocular disorders characterised by angiogenesis, which employ multiple intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) antibodies. Synthesis of a polyethylene glycol-polycaprolactone-polyethylene glycol (PEG-PCL-PEG) triblock co-polymer was undertaken, followed by characterisation employing Fourier-transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy and differential scanning calorimetry (DSC) to ascertain the chemical stability and integrity of the co-polymer instituted for nano-thermogel formulation. The p11 anti-angiogenic peptide underwent encapsulation within poly(lactic-co-glycolic acid) (PLGA) nanoparticles via a double emulsion solvent evaporation method and was incorporated into the thermogel following characterisation by scanning electron microscopy (SEM), zeta size and zeta-potential analysis. The tube inversion approach and rheological analysis were employed to ascertain the thermo-sensitive sol-gel conversion of the nano-thermogel system. Chromatographic assessment of the in vitro release of the peptide was performed, with stability confirmation via Tris-Tricine PAGE (Polyacrylamide Gel Electrophoresis). In vitro biocompatibility of the nano-thermogel system was investigated employing a retinal cell line (ARP-19). A nanoparticle size range of 100–200 nm and peptide loading efficiency of 67% was achieved. Sol-gel conversion of the nano-thermogel was observed between 32–45 °C. Release of the peptide in vitro was sustained, with maintenance of stability, for 60 days. Biocompatibility assessment highlighted 97–99% cell viability with non-haemolytic ability, which supports the potential applicability of the nano-thermogel system for extended delivery of peptide for ocular disorder treatment.

PH‐Sensitive Polymeric Poly (ϵ‐caprolactone) Core‐ Chitosan/Alginate Shell Particle System for Oral Insulin Delivery

AbstractOral administration of the drugs is considered as one of the most convenient and comfortable routes. However, an effective oral delivery of insulin still remains a challenging and elusive goal, due to bioavailability problem. The aim of our work is to develop a pH sensitive polymeric system for the oral delivery of insulin based on a poly (ϵ‐caprolactone) (PCL) core and shells of chitosan (CS) and alginate (ALG). The particles were prepared based on the double emulsion (water/oil/water) solvent evaporation method. The effect of blending Pluronic127 (F127) into the hydrophobic PCL matrix to improve its water permeability by increasing specific surface area. ALG have been chosen to provide the needed pH‐sensitivity to the system. However, to coat the PCL surface with this anionic ALG layer a cationic CS layer has been added. The influence of each of the CS and ALG layers on the nanoparticle's physiochemical properties as well as on the encapsulation efficiency and the drug release behavior of the nanoparticles was investigated. The results showed that CS and ALG shells increased the stability of the nanoparticles. The in vitro release studies using two different pH environments (1.2 and 6.8) to simulate the physiological conditions in the gastrointestinal tract (GIT) showed that, the particles have pH‐responsive release patterns. The kinetics studies showed that, the insulin release from all the particles formulations obey the Korsmeyer‐ Peppas kinetic model.

Preparation of poly (lactic-co-glycolic acid)-loaded pentoxyfilline by nanoparticipation technique

Background: Nanomaterial concerned to an incidental, natural, or synthesized material containing particles utilized for curing several diseases and keeping for human with animals health; it is either in an unbound condition or as a combination in which one or more external measurements in the size range of 1–100 nm. Objectives: The study intended to assess the possible mitigating outcome of the reference pentoxifylline by progressed a new manner of poly (lactic-co-glycolic acid) (PLGA) nanoparticles loading with pentoxifylline on induced thin layer endometrial in female rats. Materials and Methods: PLGA nanoparticle was made by employing two procedures included nanoprecipitation technique and double emulsion solvent evaporation method. The experiment firstly was achieved numerous of diagnostic tests to the knowledge of PLGA nanoparticle characteristics that involved ultraviolet (UV) spectrophotometer test. Results: UV spectrophotometer test shown for Pentoxyfilline absorbance (0.300124), at wave length (2979) and PLGA- loaded Pentoxyfilline absorbance (3.07877), at wave length 1565), while other tests (scanning electron microscope, cumulative %; encapsulation drug efficiency loading, and zeta) of PLGA-nanoparticle appeared (28.35 nm-35.45 nm, (8.48, 93.3 at maximum wavelength 275 nm, (−13.44 mV), with mobility (−1.05 [μ/s]/[V/cm]) respectively. Conclusion: Regarding the characterization of PLGA displayed in this study, it can be concluded that DMSO related organic phase alone gives the shape, particle size with a small diameter, negatively charged in addition to suitable LD, EE with suitable stabilizer. Also, PLGA-Pentoxyfilline regimen treatment with different doses had the ability in recovery of female rats that exposed experimentally induced thin layer endometrium in the uterine horn by ethanol.

Engineering of Solid Dosage Forms of siRNA-Loaded Lipidoid-Polymer Hybrid Nanoparticles Using a Quality-by-Design Approach.

Therapy based on RNA interference (RNAi), which can be mediated by exogenous small interfering RNA (siRNA), has potential for the management of diseases at the genetic level by silencing gene function(s). In all eukaryotic cells, RNAi is an endogenous regulatory mechanism, where messenger RNA (mRNA) is degraded, preventing its translation into protein. A significant advantage of RNAi therapy is that siRNA is very potent and gene silencing is highly specific, ensuring few off-target effects. However, the delivery of exogenous siRNA to the RNAi pathway in the cytosol is a challenge, and there is a need for development of advanced delivery systems to ensure safe and effective delivery of siRNA to the intracellular target site. Recently, we demonstrated the ability of lipid-polymer hybrid nanoparticles (LPNs) composed of cationic lipidoid 5 (L5) and the biodegradable polymer poly(DL-lactic-co-glycolic acid) to effectively deliver siRNA directed against tumor necrosis factor alpha (TNF-α) intracellularly to macrophages. L5 is a novel lipid-like material consisting of a tetraamine backbone linked to five C12 alkyl chains. Here, we describe a systematic quality-by-design (QbD) approach including risk assessment and design of experiments to investigate the influence of critical formulation parameters (i.e., L5 content and L5:TNF-α siRNA ratio (w/w)) on the physicochemical properties and the TNF-α gene silencing ability of TNF-α siRNA-loaded LPNs, prepared by using a double emulsion solvent evaporation method. We then detail protocols for the manufacturing of more stable solid dosage forms of LPNs using freeze drying and spray drying processes, respectively. We also provide protocols for characterization of the physicochemical properties of the nanocomposite dry powders, including (1) process yield, (2) aerodynamic particle size, (3) surface morphology, (4) moisture content, and (5) solid state properties. General considerations are provided that emphasize the advantages and disadvantages of applying QbD approaches for optimizing nanoparticulate formulations.

Preparation and characterization of ethylcellulose microspheres for sustained-release of pregabalin.

Background and purpose:Pregabalin is used in the treatment of epilepsy, chronic pain, and other psychological disorders. Preparation of pregabalin in the sustained-release formulation will enhance patient compliance and reduce the incidence of side effects. The aim of this study was to prepare sustained-release microspheres for pregabalin utilizing ethylcellulose and evaluate the processing factors that influence the fabrication and the performance of the prepared microspheres.Experimental approach:The microspheres were prepared using the water-oil-oil double emulsion solvent evaporation method. Microspheres were characterized for particle size, encapsulation efficiency, and in vitro drug release. The influence of the processing variables on the characteristics of the prepared microspheres was studied. Microspheres solid-state characterization performed using differential scanning calorimetry, Fourier transform infrared spectroscopy and scanning electron microscopy.Findings/Results:The results described in the context of the current work illustrated the suitability of the water-oil-oil system in the preparation of sustained-release microspheres for pregabalin. The optimum formulation was prepared at a drug to polymer ratio of 1:3 w/w, stirring speed of 600 rpm, surfactant concentration of 1.5%, and external phase volume of 150 mL. This formula produced microspheres particle size in the range 600-1000 μm, with 87.6% yield, and 80.14 ± 0.53% encapsulation efficiency. Drug release from the microspheres was found to be diffusion controlled, with a pH-independent behavior.Conclusion and implicationThe current work presented a successful attempt to fabricate a sustained-release microsphere comprising pregabalin. This will help overcome the frequent dosing problems with conventional pregabalin dosage forms and improve product performance.

Exploration of bromelain laden nanostructured lipid carriers: An oral platform for bromelain delivery in rheumatoid arthritis management

Bromelain, a cysteine protease exhibits promising potential in amelioration of wide variety of inflammatory disorders. Its denaturation or aggregation in gastric milieu depletes its therapeutic potential along with unpredictable prophylactic hypersensitivity reactions. Hence, efficient carrier system to improve bromelain’s stability and avoid related side effects is of utmost importance. Therefore, present investigation was undertaken to prepare bromelain loaded nanostructured lipid carriers (Br-NCs) with high drug loading, stability and efficacy in rheumatoid arthritis management. Br-NCs fabricated via double emulsion solvent evaporation method were characterized for physical properties, morphology and stability. Optimized batch exhibited spherical shape, nanometric size (298.23 nm) and entrapment efficiency ~77% with sustained release behavior and improved gastric stability. Br-NCs exhibited 4.63-folds improvement in shelf-life compared to bromelain at room temperature. The protective potential of orally administered Br-NCs in rheumatoid arthritis was evaluated via assessing arthritis severity in wistar rats along with biochemical, hematological and immunological parameters. Br-NCs remarkably (p < 0.05) diminished paw edema, joint stiffness, mechanical allodynia and tissue damage along with alleviation of oxidative stress and immunological markers. Radiological joint alterations were also notably preserved with Br-NCs. Thus, preclinical studies distinctly manifested that Br-NCs formulation opens new avenue for development of novel effective therapeutic modality for rheumatoid arthritis management.

CD44-Targeting Oxygen Self-Sufficient Nanoparticles for Enhanced Photodynamic Therapy Against Malignant Melanoma.

ObjectiveNanotechnology-based photodynamic therapy (PDT) is a relatively new anti-tumor strategy. However, its efficacy is limited by the hypoxic state in the tumor microenvironment. In the present study, a poly(lactic-co-glycolic acid) (PLGA) nanoparticle that encapsulated both IR820 and catalase (CAT) was developed to enhance anti-tumor therapy.Materials and MethodsHA-PLGA-CAT-IR820 nanoparticles (HCINPs) were fabricated via a double emulsion solvent evaporation method. Dynamic light scattering (DLS), transmission electron microscopy (TEM), laser scanning confocal microscopy, and an ultraviolet spectrophotometer were used to identify and characterize the nanoparticles. The stability of the nanoparticle was investigated by DLS via monitoring the sizes and polydispersity indexes (PDIs) in water, PBS, DMEM, and DMEM+10%FBS. Oxygen generation measurement was carried out via visualizing the oxygen bubbles with ultrasound imaging system and an optical microscope. Inverted fluorescence microscopy and flow cytometry were used to measure the uptake and targeting effect of the fluorescent-labeled nanoparticles. The live-dead method and tumor-bearing mouse models were applied to study the HCINP-induced enhanced PDT effect.ResultsThe results showed that the HCINPs could selectively target melanoma cells with high expression of CD44, and generated oxygen by catalyzing H2O2, which increased the amount of singlet oxygen, ultimately inhibiting tumor growth significantly.ConclusionThe present study presents a novel nanoplatform for melanoma treatment.

Novel Silibinin Loaded Chitosan-Coated PLGA/PCL Nanoparticles Based Inhalation Formulations with Improved Cytotoxicity and Bioavailability for Lung Cancer

Silibinin is widely used as an anticancer agent. There are important matters of concern regarding the drug pharmacokinetics related to the conventional formulation due to their low solubility and bioavailability. The aim of the present investigation was to develop, characterize, and evaluate chitosan-coated PLGA/PCL nanoparticles containing Silibinin (SB) intended for pulmonary delivery for treating lung cancer. Nanoparticles were prepared by double emulsion solvent evaporation method followed by lyophilized to obtain inhalation powder form. The prepared nanoparticles (NPs) were evaluated for their physicochemical characteristic along with DSC, FTIR, and SEM. The anticancer activity of SB-loaded NPs was assessed in the human A549 lung cancer cell line utilizing MTT assay and anti-cancer potential assessed by clonogenic assay. The pharmacokinetics and tissue distribution studies of SB-loaded NPs were assessed in comparison with the SB solution. The prepared NPs exhibited particle sizes in the range of 187–284 nm. Zeta potential was altered from negative to positive due to the coating with chitosan. Chitosan-coated NPs showed the sustain release effect up to 48 h with an aerodynamic particle size of 1.82 μm. Moreover, a tremendous increase in cell inhibition was determined by chitosan-coated PLGA NPs. Pharmacokinetics study showed that chitosan coating onto PLGA nanoparticles promoted to release drug in the lungs and increased vivo residence time. Thus, proposed formulations with improved bioavailability can be useful for efficient pulmonary delivery. These nanoparticles coated with chitosan could open a new avenue for effective treatment of lung cancer.

Nano-co-delivery of lipophosphoglycan with soluble and autoclaved leishmania antigens into PLGA nanoparticles: Evaluation of in vitro and in vivo immunostimulatory effects against visceral leishmaniasis

The aim of the present study was to encapsulate lipophosphoglycan molecule (LPG) which is one of the most immunogenic antigens of Leishmania parasites into PLGA nanoparticles with autoclaved or soluble leishmanial antigens, characterize synthetized nanoparticles with different methods and evaluate their in vitro/in vivo immunostimulatory activities to develop new vaccine candidates. PLGA nanoparticles including LPG and autoclaved leishmania antigen (ALA) or soluble leishmania antigen (ALA) were synthetized by double emulsion solvent evaporation method. The synthetized nanoparticles were characterized by SEM and Zeta-sizer instruments for determination of size, zeta potentials and polydispersity index (PDI) values. The antigen release profiles and encapsulation efficiencies were determined by UV–Vis spectroscopy. Griess reaction and ELISA tests were used for measurements of produced nitric oxide (NO) and cytokine levels of macrophages and splenocytes treated with nanoparticles. For determination of protective effects of nanoparticles, parasite reduction in livers and spleens of immunized mice were calculated by LDU values post-infection. According to results, (SLA-LPG) PLGA NPs and (ALA-LPG) PLGA NPs possessed the sizes of 253 and 307 nm respectively. Antigen-loaded nanoparticles elevated the released NO amounts from macrophages for 14 and 18-folds in contrast to control. Furthermore, synthetized nanoparticles significantly triggered macrophages to produce excessive levels of IFN-γ and IL-12 cytokines. Besides it was detected that vaccination of mice with (SLA-LPG) PLGA NPs and (ALA-LPG) PLGA NPs elicited approximately 80% protection from Visceral Leishmaniasis. Furthermore, (SLA-LPG) PLGA NPs and (ALA-LPG) PLGA NPs lead to 10 to 14-folds increase in secreted Th1 cytokine levels from splenocytes than control demonstrating abundantly stimulation of T cell response following to vaccination with nano-vaccine formulations. These results reveal that both (SLA-LPG) PLGA NPs and (ALA-LPG) PLGA NPs have excellent immunostimulatory activities and they are promising nanovaccine formulations for the prevention of leishmaniasis in near future.

Dexamethasone Sodium Phosphate Loaded Modified Cyclodextrin Based Nanoparticles: An Efficient Treatment for Rheumatoid Arthritis.

The main aim of the current research was to develop a modified cyclodextrin based nanoparticulate drug delivery system to deliver dexamethasone sodium phosphate (DSP) for the treatment of rheumatoid arthritis (RA). DSP is a glucocorticoid (GC), and its limited application in RA therapy due to poor pharmacokinetics and its severe associated side effects. DSP loaded hydrophobically modified cyclodextrin based nanoparticles (DSP-NPs) prepared by a double emulsion solvent evaporation method. The nanoparticle size was <120nm, good entrapment efficiency and excellent stability were obtained. TEM study showed that nanoparticles were perfectly spherical shape. The in-vitro drug release from nanoparticle follows the non-Fickian diffusion mechanism. The pharmacokinetic profile of DSP after encapsulation showing the 2.3-fold increase in AUC and extended mean residence time, which increases the chances of nanoparticles to extravasate into the site of inflammation by the EPR effect. The pharmacodynamic studies in the Adjuvant-induced Arthritis (AIA) rat model showing a significant reduction in arthritic score, paw thickness, and inflammatory cytokine level in serum. Adverse effects evaluation studies demonstrate a significant reduction in the associated undesirable effects on body weight, blood glucose level, renal impairment, and hematological abnormalities compared to marketed formulation. These results suggest that DSP-NPs can be used as an efficient therapy for RA.

Design and fabrication of novel multi-targeted magnetic nanoparticles for gene delivery to breast cancer cells

In this study, a novel multi-targeted magnetic nanoparticles (MTMNPs) are synthesized to investigate their potential application in DNA protection and targeted gene delivery to breast cancer cells. In the present study MTMNPs was prepared from polyethyleneimine coated Fe3O4 nanoparticles, polyethyleneimine-polylactic acid-polyethylene glycol-folic acid copolymer (PEI-PLA-PEG-FA) and DNA using double-emulsion solvent evaporation method. The EPPT peptide (Glu-Pro-Pro-Thr) is also incorporated into the MTMNPs as a targeting agent for overexpressed MUC-1 receptors on breast cancer cells. The DNA release ratio from the MTMNPs nanoparticles were significantly decreased with increasing the pH value and decreasing the temperature. The capability of the MTMNPs nanoparticles to protect the DNA from nuclease digestion and ultrasound damage were confirmed by gel electrophoresis assay. In vitro results demonstrated a novel MFMNPs nanoparticle remarkably reduced PEI-associated toxicity on MCF-7 cells, compared to PEI/DNA complex. Moreover, the MFMNPs improved the efficiency of gene delivery in 10% serum medium by more than 2.98-fold, compared to PEI/DNA complex.

Development and optimization of vitamin E TPGS based PLGA nanoparticles for improved and safe ocular delivery of ketorolac

Topical ocular delivery of therapeutics are always a challenging arena in order to achieve high ocular bioavailability with safe administration. Ideal ocular delivery of drug required 4 P's that is Patient compliance, Prolong retention, Penetration to cornea and Prolong release of drug. In an attempt to achieve desired characteristics for ocular delivery, Ketorolac loaded PLGA nanoparticles were fabricated by double emulsification solvent evaporation method and optimized by employing response surface methodology (RSM) followed by statistical analysis. Results obtained by RSM were further validated for fitness in model by different checkpoint formulations. Vitamin E TPGS was selected as emulsifier, which acquires high emulsifying capability and high permeability character. Zeta-size study revealed that optimized formulation has mean particle size 142.8 ± 11.7 nm, which was in agreement of TEM study and zeta potential was found −24.2 ± 1.2 mV. Encapsulation efficiency was achieved 63.5 ± 8.4%. Release profile was established by different mathematical modelling. It was observed that optimized formulation showed sustained release and followed by Korsmeyer-Peppas model. Corneal transport study showed enhanced drug permeation as compared to drug solution. HET-CAM test and histopathology studies revealed that optimized PLGA NPs was non-irritant and safe for ocular application.

A novel injectable fibroblasts-porous PDLLA microspheres/collagen gel composite for soft-tissue augmentation

This study designed a novel porous PDLLA microspheres/collagen gel composite combined with fibroblasts as the injectable dermal filler for soft-tissue augmentation. The low degradation rate of porous PDLLA microspheres and seed cells were introduced in the system to achieve the filling volume stability and stronger regeneration activity. Biodegradable PDLLA porous microspheres were prepared by an improved water-in-oil-in-water double emulsion solvent evaporation method. The combine of fibroblasts with porous microspheres was observed through co-culture of cells with microspheres, SEM (scanning electron microscope) and fluorescent staining technology. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, the hemolysis test and histocompatibility experiment indicated that the composite had satisfactory biocompatibility in vitro and in vivo. In the animal studies, the composite was implanted into the subcutaneous part of the rats’ back through sterile needles. The collagen was metabolized within 30 days, meanwhile, fibroblasts-porous PDLLA microspheres served as scaffold structure and seed cells which promote new connective tissue formation. The histopathological studies demonstrate that the fibroblasts-porous PDLLA microspheres/collagen gel composite group could create larger amount of supportive structure than PDLLA porous microspheres/collagen gel composite group. All the results indicate that fibroblasts-porous PDLLA microspheres/collagen gel composite may have great clinical application in soft-tissue augmentation with its excellent biocompatibility, regeneration activity and stable long-term filling ability.

Novel Polymeric Hybrid Nanocarrier for Curcumin and Survivin shRNA Co-delivery Augments Tumor Penetration and Promotes Synergistic Tumor Suppression.

A major barrier for co-delivery of gene medicine with small molecular chemotherapeutic drugs in solid tumors is the inadequate tumor penetration and transfection. In this study, a novel polymeric nanocarrier with integrated properties of tumor penetration, nuclear targeting, and pH-responsive features was designed, and further used to achieve the synergistic anti-tumor effect of curcumin (CUR) and survivin shRNA (pSUR). The polymeric hybrid nanocarrier was constructed from the FDA-approved polymer PLGA and a novel conjugated triblock polymer W5R4K-PEG2K-PHIS (WPH). CUR and pSUR were simultaneously encapsulated in the dual-drug-loaded nanoparticles (CUR/pSUR-NPs) by a modified double-emulsion solvent evaporation (W/O/W) method. The obtained nanoparticles exhibited better pharmaceutical properties with a uniform spherical morphology and sustained release manners of CUR and pSUR. Excellent features including preferable cellular uptake, efficient endosomal escape, enhanced tumor penetration, and elevated transfection efficiency were further proven. Additionally, a markedly enhanced anti-tumor efficacy for CUR/shRNA-NPs was achieved on SKOV-3 and Hela cells. The synergistic anti-tumor effect involved the inhibition of tumor cell proliferation, induction of cell apoptosis, and the activation of caspase-3 pathways. This work sets up an innovative co-delivery nanosystem to suppress tumor growth, contributing to the development of a comprehensive nanoparticulate strategy for future clinical applications.

A Study on Chitosan Coated Polycaprolactone (Ch-PCL) Microspheres Prepared via Double Emulsion Solvent Evaporation Method

Polycaprolactone coated with chitosan microspheres have the potential to be used as delivery systems and biosensors. Polycaprolactone (PCL) is, however hydrophobic, to improve the biofunctional and potential immobilization of PCL polymer, chitosan-coated PCL microspheres (MSs) were prepared using a double emulsion solvent evaporation method. Different particle sizes were prepared by altering five parameters. When the MSs were prepared using oil to water phase ratio or oil fraction (ϕo) of ϕo = 0.95 to ϕo = 0.38, the MSs average diameter (Dv) reduced from 3.86 to 3.53 µm along with its coefficient of variation (CV), reduced from 18.1 to 12.3 respectively. The MSs prepared with higher polymer concentration of 6wt.% shows higher Dv (4.51 µm) and CV (25.2) compared to 1.2wt.% of PCL, which Dv = 3.86 µm with CV of 18.1. The first homogenizer speed (H1) was increased in order to prepare smaller MSs. When H1 increased from 6 000 to 10 000 rpm, MSs Dv reduced from 3.86 to 3.45 µm along with its CV reduce from 18.1 to 16.6 for ϕo = 0.95. It is also the same case for ϕo = 0.52, where the Dv reduced from 3.70 to 3.19 µm and its CV reduce from 25.8 to 25.2. The effect of NaCl concentration on MSs preparation shows, higher NaCl concentration (1.8wt.%) produced smaller Dv(Dv = 3.86 µm) compared to lower concentration of 0.9wt.%, produced Dv = 4.51 µm for ϕo = 0.95. The trend also follows when the MSs were prepared for ϕo = 0.52. The delay in adding the NaCl shows distinct effect on Dv. For both 0.9 and 1.8 wt.% of NaCl, the Dv increase from 4.51 to 6.40 µm and 4.31 to 6.17 µm respectively. Therefore, the targeted Dv for certain application could be achieved by altering the parameters above. Finally, to study the Ch-PCL potential as enzyme immobilizer, horseradish peroxidase (HRP) was used to be immobilized on to the Ch-PCL MSs. After 7 days, the HRP enzyme still show 51% activity under robust storage condition.

Shear Speed-Regulated Properties of Long-Acting Docetaxel Control Release Poly (Lactic-Co-Glycolic Acid) Microspheres.

Advanced drug carriers for the controlled release of chemotherapeutics in the treatment of malignant tumors have drawn significant notice in recent years. In the current study, microspheres (MPs) loaded with docetaxel (DTX) were prepared using polylactic-co-glycolic acid copolymer (PLGA). The double emulsion solvent evaporation method is simple to perform, and results in high encapsulation efficiency. Electron micrographs of the MPs showed that controlling the shear rate can effectively control the size of the MPs. At present, most DTX sustained-release carriers cannot maintain stable and long-term local drug release. The 1.68 μm DTX-loaded microspheres (MP/DTX) with elastase was completely degraded in 14 d. This controlled degradation period is similar to a course of treatment for most cancers. The drug release profile of all kinds of MP/DTX demonstrated an initial rapid release, then slower and stable release to the end. The current study demonstrates that it is possible to create drug-loaded MPs with specific degradation times and drug release curves, which may be useful in achieving optimal treatment times and drug release rates for different diseases, and different drug delivery routes. The initial burst release reaches the effective concentration of the drug at the beginning of release, and then the drug concentration is maintained by stable release to reduce the number of injections and improve patient compliance.

Radachlorin-Containing Microparticles for Photodynamic Therapy.

Purpose: Reducing the undesirable systemic effect of photodynamic therapy (PDT) can be achieved by incorporating a photosensitizer in microparticles (MPs). This study is devoted to the preparation of biocompatible biodegradable MPs with the inclusion of the natural photosensitizer Radachlorin (RС) and an assessment of the possibility of their use for PDT. Methods: RC-containing MPs (RС MPs) with poly(lactic-co-glycolic acid) copolymer (PLGA) matrix were prepared by a double emulsion solvent evaporation methods. The size and morphology of RC MPs were surveyed using scanning electron microscopy, confocal laser scanning microscopy, and dynamic light scattering. The content of RC, its release from RC MPs, and singlet oxygen generation were evaluated by the optical spectroscopy. Cellular uptake and cytotoxic photodynamic effect of RC MPs were investigated with in vitro assays.Results: The average diameter of the prepared RC MPs was about 2-3 μm. The RC MPs prepared by the water/oil/oil method had a significantly higher inclusion of RC (1.74 μg/mg) then RC MPs prepared by the water/oil/water method (0.089 μg/mg). Exposure of the prepared RC MPs to PDT light radiation was accompanied by the singlet oxygen generation and a cytotoxic effect for tumor cells. The release of the RC from the RC MPs was prolonged and lasted at least two weeks.Conclusion: PLGA RC MPs were found to cause a photoactivated cytotoxic effect for tumor cells and can be used for local application in PDT of tumors.

Immune Responses to Varicella-Zoster Virus Glycoprotein E Formulated with Poly(Lactic-co-Glycolic Acid) Nanoparticles and Nucleic Acid Adjuvants in Mice

The subunit herpes zoster vaccine Shingrix is superior to attenuated vaccineZostavax in both safety and efficacy, yet its unlyophilizable liposome delivery system and the limited supply of naturally sourced immunological adjuvant QS-21 still need to be improved. Based on poly(lactic-co-glycolic acid) (PLGA) delivery systems that are stable during the lyophilization and rehydration process and using a double-emulsion (w/o/w) solvent evaporation method, we designed a series of nanoparticles with varicella-zoster virus antigen glycoprotein E (VZV-gE) as an antigen and nucleic acids including polyinosinic-polycytidylic acid (Poly I:C) and phosphodiester CpG oligodeoxynucleotide (CpG ODN), encapsulated as immune stimulators. While cationic lipids(DOTAP) have more potential than neutral lipids(DOPC) for activating gE-specific cell-mediated immunity (CMI) in immunized mice, especially when gE is encapsulated in and presented on the surface of nanoparticles, PLGA particles without lipids have the greatest potential to induce not only the highest gE-specific IgG titers but also the strongest gE-specific CMI responses, including the highest proportions of interferon-γ (IFN-γ)- and interleukin-2 (IL-2)-producing CD4+/CD8+ T cells according to a flow cytometry assay and the greatest numbers of IFN-γ- and IL-2-producing splenocytes according to an enzyme-linked immunospot (ELISPOT) assay. These results showed that immune-stimulating nucleic acids together with the PLGA delivery system showed promise as a safe and economical varicella and zoster vaccine candidate.