Double Emulsion Solvent Evaporation Method Research Articles

Brain delivery of baclofen as a hydrophilic drug by nanolipid carriers: Characteristics and pharmacokinetics evaluation

Formulation of baclofen in lipid-based nanoparticles may be helpful to overcome its difficulties in order to reach the site of action in the CNS. This study reports production, characterization and pharmacokinetics evaluation of baclofen loaded lipid nano-carriers. Lipid nano-carriers containing baclofen were prepared by using double emulsion solvent evaporation method and physicochemical characteristics of prepared nanoparticles were evaluated. The selected formulation was administered on rat model to be compared with an aqueous drug solution. Plasma and brain concentrations of drug and pharmacokinetics parameters were compared. Nanostructured lipid carriers (NLC) formulation showed better physicochemical properties than solid lipid nanoparticles (SLNs). Also, the formulation of baclofen by NLC increased the half-life of drug in plasma and brain up to 10 and 1.5 times respectively compared to the solution formulation. Results revealed a more significant and prolonged effect of baclofen-NLC in comparison with baclofen solution in both plasma and brain mediums that emphasize and prove theories on the formulation of hydrophilic drug in NLCs can be a solution for target drug delivery to the brain.

Preparation and Characterization of Polymeric Nanoparticles: An Interdisciplinary Experiment

In this work, a laboratory experiment to introduce graduate students to nanotechnology is described. Students prepared poly(lactic-co-glycolic acid) (PLGA) nanoparticles using two different synthesis procedures, a single and a double emulsion–solvent evaporation method. The students also performed a physicochemical characterization of the prepared nanoparticles (NPs) by determining the hydrodynamic size and zeta potential values through Dynamic and Electrophoretic Light Scattering, respectively. The experiments were designed to be accomplished in two 180 min sessions and have been successfully conducted by 24 graduate students.

Improved mucoadhesion and cell uptake of chitosan and chitosan oligosaccharide surface-modified polymer nanoparticles for mucosal delivery of proteins.

The main aim of the present study was to compare mucoadhesion and cellular uptake efficiency of chitosan (CS) and chitosan oligosaccharide (COS) surface-modified polymer nanoparticles (NPs) for mucosal delivery of proteins. We have developed poly (D, L-lactide-co-glycolide) (PLGA) NPs, surface-modified COS-PLGA NPs and CS-PLGA NPs, by using double emulsion solvent evaporation method, for encapsulating bovine serum albumin (BSA) as a model protein. Surface modification of NPs was confirmed using physicochemical characterization methods such as particle size and zeta potential, SEM, TEM and FTIR analysis. Both surface-modified PLGA NPs displayed a slow release of protein compared to PLGA NPs. Furthermore, we have explored the mucoadhesive property of COS as a material for modifying the surface of polymeric NPs. During in vitro mucoadhesion test, positively charged COS-PLGA NPs and CS-PLGA NPs exhibited enhanced mucoadhesion, compared to negatively charged PLGA NPs. This interaction was anticipated to improve the cell interaction and uptake of NPs, which is an important requirement for mucosal delivery of proteins. All nanoformulations were found to be safe for cellular delivery when evaluated in A549 cells. Moreover, intracellular uptake behaviour of FITC-BSA loaded NPs was extensively investigated by confocal laser scanning microscopy and flow cytometry. As we hypothesized, positively charged COS-PLGA NPs and CS-PLGA NPs displayed enhanced intracellular uptake compared to negatively charged PLGA NPs. Our results demonstrated that CS- and COS-modified polymer NPs could be promising carriers for proteins, drugs and nucleic acids via nasal, oral, buccal, ocular and vaginal mucosal routes.

English

The objective of this study was to design nano-antibiotic to enhance their release from biomaterial agents. Cefotaxime was used as a model antibiotic substance in this carrier system. These nanoparticles were preformulated using different concentrations of polycaprolactone (PCL) and poly (vinyl alcohol) as coating material and prepared using double emulsion solvent evaporation method. The physiochemical properties of cefotaxime nano-antibiotic (Cefo-NPs) stability were determined. Results showed that the encapsulation efficiency of nanoparticles increased with increase in polymer concentration. In addition, dynamic light scattering (DLS) and atomic force microscope (AFM) indicated that the particles size were in the range of 189 to 219 nm. The drug release profile of Cefo-NPs shows rapidly the release behaviour under acidic environment. And thus make it a promising tool for control bacterial infection. Key words: Polycaprolactone, poly (vinyl alcohol), cefotaxime, nanoparticle.

Fabrication of hollow porous PLGA microspheres using sucrose for controlled dual delivery of dexamethasone and BMP2

Hollow porous poly(d,l-lactide-co-glycolide) microspheres (HP-PLGA-MS) were manufactured using the water-in-oil-in-water double emulsion solvent evaporation method with sucrose as a novel porogen. Dexamethasone (DEX) was dissolved in the oil phase and loaded during the preparation of the HP-PLGA-MS. Bone morphogenetic protein-2 (BMP2) with type I collagen (Col1) was incorporated into HP-PLGA-MS using a simple immersion method. The release rate of BMP2 could be controlled by the amount of Col1. DEX and BMP2 showed a sustained release profile. These results showed that the HP-PLGA-MS could be fabricated successfully using sucrose and showed great potential as a controlled dual drug delivery system.

Development and statistical optimization of chitosan and eudragit based gastroretentive controlled release multiparticulate system for bioavailability enhancement of metformin HCl

The present research was intended to develop a gastroretentive controlled release multiparticulate delivery system for a hypoglycemic drug, metformin hydrochloride (MTF) that could efficiently deliver the drug in active form and also increase its systemic bioavailability. In vitro and in vivo evaluations were performed to determine the efficacy of the formulation. MTF loaded microspheres were prepared by W/O/O double emulsion-solvent evaporation method and optimized by 32 full factorial design. The ratio of eudragit RL100 & RS100 (EL:ES) and the chitosan concentration were evaluated as independent variables for dependent variables viz. percent drug release (%DR), percent yield (%Y) and encapsulation efficiency (EE). The morphological characteristics of the microspheres were assessed using scanning electron microscopy which revealed non-aggregated, spherical shape microspheres with rough and rugged surfaces. The particle size range of the formulated microspheres was found to be ~74.77–111.18 µm. In vitro drug release best fitted Korsmeyer Peppas release characteristics with Fickian diffusion release mechanism. The optimized batch F1 demonstrated 84.17 ± 5.80 % drug release, 85.47 ± 0.28 % yield and 70.79 ± 0.67 % EE. Optimized batch performed superior pharmacokinetics with prolonged and increased intensity of hypoglycemic effect (87.68 ± 4.9 %) a relative bioavailability of 154.71 % with respect to the marketed product (56.67 ± 4.7 %). These findings highlight the potential of formulated microparticles as a superior candidate for gastro-retentive sustained release delivery of MTF with respect to marketed product.

The synergic antitumor effects of paclitaxel and temozolomide co-loaded in mPEG-PLGA nanoparticles on glioblastoma cells.

To get better chemotherapy efficacy, the optimal synergic effect of Paclitaxel (PTX) and Temozolomide (TMZ) on glioblastoma cells lines was investigated. A dual drug-loaded delivery system based on mPEG-PLGA nanoparticles (NPs) was developed to potentiate chemotherapy efficacy for glioblastoma. PTX/TMZ-NPs were prepared with double emulsification solvent evaporation method and exhibited a relatively uniform diameter of 206.3 ± 14.7 nm. The NPs showed sustained release character. Cytotoxicity assays showed the best synergistic effects were achieved when the weight ratios of PTX to TMZ were 1:5 and 1:100 on U87 and C6 cells, respectively. PTX/TMZ-NPs showed better inhibition effect to U87 and C6 cells than single drug NPs or free drugs mixture. PTX/TMZ-NPs (PTX: TMZ was 1:5(w/w)) significantly inhibited the tumor growth in the subcutaneous U87 mice model. These results indicate that coordinate administration of PTX and TMZ combined with NPs is an efficient method for glioblastoma.

Therapeutic Use of 3β-[N-(N',N'-Dimethylaminoethane) Carbamoyl] Cholesterol-Modified PLGA Nanospheres as Gene Delivery Vehicles for Spinal Cord Injury.

Gene delivery holds therapeutic promise for the treatment of neurological diseases and spinal cord injury. Although several studies have investigated the use of non-viral vectors, such as polyethylenimine (PEI), their clinical value is limited by their cytotoxicity. Recently, biodegradable poly (lactide-co-glycolide) (PLGA) nanospheres have been explored as non-viral vectors. Here, we show that modification of PLGA nanospheres with 3β-[N-(N′,N′-dimethylaminoethane) carbamoyl] cholesterol (DC-Chol) enhances gene transfection efficiency. PLGA/DC-Chol nanospheres encapsulating DNA were prepared using a double emulsion-solvent evaporation method. PLGA/DC-Chol nanospheres were less cytotoxic than PEI both in vitro and in vivo. DC-Chol modification improved the uptake of nanospheres, thereby increasing their transfection efficiency in mouse neural stem cells in vitro and rat spinal cord in vivo. Also, transgene expression induced by PLGA nanospheres was higher and longer-lasting than that induced by PEI. In a rat model of spinal cord injury, PLGA/DC-Chol nanospheres loaded with vascular endothelial growth factor gene increased angiogenesis at the injury site, improved tissue regeneration, and resulted in better recovery of locomotor function. These results suggest that DC-Chol-modified PLGA nanospheres could serve as therapeutic gene delivery vehicles for spinal cord injury.

Inhibition of Octreotide Acylation Inside PLGA Microspheres by Derivatization of the Amines of the Peptide with a Self-Immolative Protecting Group.

Acylation of biopharmaceuticals such as peptides has been identified as a major obstacle for the successful development of PLGA controlled release formulations. The purpose of this study was to develop a method to inhibit peptide acylation in poly(d,l-lactide-co-glycolide) (PLGA) formulations by reversibly and temporarily blocking the amine groups of a model peptide (octreotide) with a self-immolative protecting group (SIP), O-4-nitrophenyl-O'-4-acetoxybenzyl carbonate. The octreotide with two self-immolative protecting groups (OctdiSIP) on the N-terminus and lysine side chain was synthesized by reaction of the peptide with O-4-nitrophenyl-O'-4-acetoxybenzyl carbonate, purified by preparative RP-HPLC and characterized by mass spectrometry. Degradation studies of OctdiSIP in aqueous solutions of different pH values showed that protected octreotide was stable at low pH (pH 5) whereas the protecting group was eliminated at physiological pH, especially in the presence of an esterase, to generate native octreotide. OctdiSIP encapsulated in PLGA microspheres, prepared using a double emulsion solvent evaporation method, showed substantial inhibition of acylation as compared to the unprotected octreotide: 52.5% of unprotected octreotide was acylated after 50 days incubation of microspheres in PBS pH 7.4 at 37 °C, whereas OctdiSIP showed only 5.0% acylation in the same time frame. In conclusion, the incorporation of self-immolative protection groups provides a viable approach for inhibition of acylation of peptides in PLGA delivery systems.

Polymeric Nanomedicine for Combined Gene/Chemotherapy Elicits Enhanced Tumor Suppression.

Combination treatment through simultaneous delivery of DNA and anticancer drugs with nanoparticles has been demonstrated to be an elegant and efficient approach for cancer therapy. Herein, we employed a combination therapy for eliminating both the tumor cells and intratumoral neovascular network based on the nanoplatform we designed. Pigment epithelium-derived factor (PEDF) gene, a powerful antiangiogenic agent, and the clinically widely used chemotherapy agent paclitaxel (PTX) were simultaneously encapsulated in the same nanoparticle by a modified double-emulsion solvent evaporation method. The dual-drug-loaded nanoparticles (D/P-NPs) exhibited a uniform spherical morphology and released PTX and PEDF gene in a sustained manner. D/P-NPs showed an enhanced antitumor effect on C26 and A549 cells and a stronger inhibitory activity on proliferation of HUVECs. Moreover, D/P-NPs could dramatically elevate the PEDF expression levels in both C26 and A549 cells in comparison with PEDF gene loaded nanoparticles and significantly promote the cellular uptake of PTX. Additionally, microtubules were stabilized and G2/M phase arrest along with a higher subG1 cell population was induced by D/P-NPs in contrast to PTX or PTX loaded nanoparticles. Besides, D/P-NPs showed sustained release of PTX and PEDF gene in tumors as well as long-term gene expression. A significantly improved anticancer effect was also demonstrated in a C26 subcutaneous tumor model using this combinational therapy. D/P-NPs could sharply reduce the microvessel density and significantly promoted tumor cell apoptosis in vivo. More importantly, the in vivo distribution, serological and biochemical analysis, and H&E staining revealed that D/P-NPs had no obvious toxicity. Our study suggested that this novel polymeric nanomedicine had great potential for improving the therapeutic efficacy of combined gene/chemotherapy of cancer.

Aptamer-modified PLGA nanoparticle delivery of triplex forming oligonucleotide for targeted prostate cancer therapy.

Presented study aimed to prepare A10 aptamer-modified poly (D,L-lactic-co-glycolic acid) (PLGA) nanoparticles loaded with triplex forming oligonucleotides(TFO) for targeted prostate cancer therapy. We first synthesized a PLGA-PEG-Apt copolymer. The PLGA-PEG-Apt nanoparticles (NP-Apt) were loaded with TFO using double emulsion solvent evaporation method. Carboxy-fluorescein labeled TFO-NP-Apt, TFO-NP and TFO were prepared for cellular uptake experiments. Cell counting kit-8 (CCK-8) test was used to determine the ability of TFO-NP-Apt to inhibit LNCaP cell proliferation. RT-PCR and Western blot was conducted to analyze AR gene expressing. Then, a mouse model of prostate cancer was used to evaluate the anti-cancer effect of TFO-NP-Apt in vivo. We confirmed that the PLGA-PEG-Apt conjugation was successful. The TFO encapsulation efficiency and drug loading percentage were 46.1± 3.6% and 40.8±5.3%, respectively. TFO-NP-Apt showed a more efficient cellular uptake than TFO-NP or TFO in LNCaP cells. TFO-NP-Apt was significantly more cytotoxic than TFO-NP and TFO in the CCK-8 test (p<0.001). TFO-NP-Apt silenced the AR gene better than unconjugated Apt, naked TFO, NP or saline. TFO-NP-Apt were more effective than TFO-NP, naked TFO, NP and saline at inhibiting prostate cancer growth in vivo (p<0.05). Aptamer-modified TFO-loaded PLGA nanoparticles may prove useful in targeted therapy for advanced prostate cancer.

Optimization of protein loaded PLGA nanoparticle manufacturing parameters following a quality-by-design approach

This paper explores the development of a multivariate-based regression model for estimating the critical attributes to establish a design-space for poly(lactic-co-glycolic acid) nanoparticles prepared by a double emulsion–solvent evaporation method.

Intranasal vaccination of mannan-decorated mucoadhesive HPMCP microspheres containing ApxIIA toxin effectively protected Actinobacillus pleuropneumoiaeinfection in mice

Event Abstract Back to Event Intranasal vaccination of mannan-decorated mucoadhesive HPMCP microspheres containing ApxIIA toxin effectively protected Actinobacillus pleuropneumoiaeinfection in mice Hui-Shan Li1, Min-Kyoung Shin2*, Bijay Singh1*, Han-Sang Yoo2*, Sushila Marharjan1*, Tae-Eun Park1*, Sang-Kee Kang3*, Zhong-Shan Hong4*, Yun-Jaie Choi1, 4* and Chong-Su Cho1 1 Seoul National University, Department of Agricultural Biotechnology & Research Institute for Agriculture and Life Sciences, Korea 2 Seoul National University, Department of Infectious Disease, College of Veterinary Medicine, Korea 3 Seoul National University, Institute of Green-Bio Science & Technology, Korea 4 Tianjin Agricultural University, Department of Animal Science, China Introduction: The nasal route for vaccine delivery by microparticles has attracted considerable interest, although challenges such as the rapid mucociliary clearance in the respiratory mucosa and the low immunogenicity of subunit vaccine still remain[1]. Recently, a new generation of synthetic polymers known as thiolated polymers, such as thiolated hydroxypropylmethyl cellulose phthalate (HPMCP),have been shown to have strong mucoadhesive properties due to their binding with the cysteine-rich subdomains of mucus glycoprotein in the mucosal site[2]. Here, we applied thiolated HPMCP (TH) to make microspheres as a nasal vaccine carrier for prolonging the residence time in the respiratory mucosa to make interaction time of vaccine molecules and antigen presenting cells (APCs) longer. Moreover, another major hurdle in the development of intranasal vaccines is poor immunogenicity of vaccine subunits due to the lack of “danger signals” that can activate APCs[3]. To this end, we aimed to develop mannan-decorated mucoadhesive THM (Man-THM) as an adjuvant system for nasal vaccine. Mannan is one of the natural PAMPs (pathogen associated molecular patterns) of APCs and is a ligand of the mannose receptor (MR) widely expressed on APCs[4],[5]. Mannan can induce the production of pro-inflammatory cytokines and up-regulate the expression of co-stimulatory molecules in these cells, thereby activating both innate and adaptive immunity[6],[7]. The aim of this work was to explore the potential of a novel Man-THM vehicle for the intranasal administration of ApxIIA as a vaccine against A. pleuropneumoniae which is known to cause contagious porcine pleuropneumoniae. Materials and Methods: ApxIIa-loaded Man-THM was prepared by the double emulsion solvent evaporation method and using the mixture of 0.25wt.-% PVA and 0.5wt.-% mannan (W2 phase) to decorate the surface of microspheres with mannan.After optimization of the preparation method and characterization of the obtained ApxIIA-loaded Man-THM, the physiochemical properties of the Man-THM as a nasal delivery carrier were evaluated by in vitro and in vivo assays. Results and Discussion: The surface of the Man-THM was homogeneously coated with mannan due to the mannan’s amphiphilic property, which functions as a stabilizer during the formation of microspheres through W1/O/W2 double emulsion. In a mechanistic study using APCs in vitro, it was found that Man-THM enhanced receptor-mediated endocytosis by stimulating the MR of APCs. In vivo, the nasal vaccination of ApxIIA-loaded Man-THM in mice resulted in higher levels of mucosal sIgA and serum IgG than mice in the ApxIIA and ApxIIA-loaded THM groups due to the specific recognition of the mannan in the Man-THM by the MRs of the APCs. Moreover, ApxIIA-containing Man-THM protected immunized mice when challenged with strains of A. pleuropneumoniae serotype 5.The number of bacteria measured in the lung tissue homogenates prepared from mice in the ApxIIA-loaded Man-THM group was approximately 100-fold lower than those from the ApxIIA and ApxIIA-loaded THM groups. Conclusion: We concluded that ApxIIA-loaded Man-THM enhanced the systemic and mucosal immune responses against ApxIIA, which enhanced the bacterial clearance ability of the mice challenged with A. pleuropneumoniae, thus improving survival. Our results strongly support the efficacy of Man-THM as an adjuvant carrier system for the effective induction of systemic and mucosal immune responses. This research was supported by the Animal Disease Management Technology Development, Ministry of Agriculture, Food and Rural Affairs, Republic of Korea. (Project code 313014-03); We also acknowledge the National Instrumental Centre for Environmental Management (NICEM) and the National Center for Inter-University Research Facilities (NCIRF).; H.S. Li and S. Marharjan were supported by BK21 plus program.

Fabrication of Fucoxanthin-Loaded Microsphere(F-LM) By Two Steps Double-Emulsion Solvent Evaporation Method and Characterization of Fucoxanthin before and after Microencapsulation.

Microencapsulation is a promising approach in drug delivery to protect the drug from degradation and allow controlled release of the drug in the body. Fucoxanthin-loaded microsphere (F-LM) was fabricated by two step w/o/w double emulsion solvent evaporation method with poly (L-lactic-coglycolic acid) (PLGA) as carrier. The effect of four types of surfactants (PVA, Tween-20, Span-20 and SDS), homogenization speed, and concentration of PLGA polymer and surfactant (PVA), respectively, on particle size and morphology of F-LM were investigated. Among the surfactants tested, PVA showed the best results with smallest particle size (9.18 µm) and a smooth spherical surface. Increasing the homogenization speed resulted in a smaller mean F-LM particle size [d(0.50)] from 17.12 to 9.18 µm. Best particle size results and good morphology were attained at homogenization speed of 20 500 rpm. Meanwhile, increased PLGA concentration from 1.5 to 11.0 (% w/v) resulted in increased F-LM particle size. The mean particle size [d(0.5)] of F-LM increased from 3.93 to 11.88 µm. At 6.0 (% w/v) PLGA, F-LM showed the best structure and external morphology. Finally, increasing PVA concentration from 0.5 to 3.5 (% w/v) resulted in decreased particle size from 9.18 to 4.86 µm. Fucoxanthin characterization before and after microencapsulation was carried out to assess the success of the microencapsulation procedure. Thermo gravimetry analysis (TGA), glass transition (Tg) temperature of F-LM and fucoxanthin measured using DSC, ATR-FTIR and XRD indicated that fucoxanthin was successfully encapsulated into the PLGA matrix, while maintaining the structural and chemical integrity of fucoxanthin.

A Controlled Release Codelivery System of MSCs Encapsulated in Dextran/Gelatin Hydrogel with TGF-β3-Loaded Nanoparticles for Nucleus Pulposus Regeneration.

Mesenchymal stem cell- (MSC-) based therapy is regarded as a potential tissue engineering strategy to achieve nucleus pulposus (NP) regeneration for the treatment of intervertebral disc degeneration (IDD). However, it is still a challenge to induce MSC differentiation in NP-like cells when MSCs are implanted into the NP. The purpose of this study was to construct poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles as carriers for TGF-β3 controlled release and establish a codelivery system of a dextran/gelatin hydrogel with the nanoparticles for long-term processing of discogenesis differentiation. TGF-β3-loaded PLGA nanoparticles were prepared by the double-emulsion solvent evaporation method and seeded uniformly into the hydrogel. Morphological observations, an assessment of the release kinetics of TGF-β3, a cytotoxic assay, a cell proliferation test, a biochemical content assay, qRT-PCR, and immunohistological analyses of the codelivery system were conducted in the study. The results showed that the TGF-β3-loaded nanoparticles could release TGF-β3 gradually. The codelivery system exhibited favorable cytocompatibility, and the TGF-β3 that was released could induce MSCs to NP-like cells while promoting ECM-related biosynthesis. These results suggest this codelivery system may be employed as a promising carrier for discogenesis of MSCs in situ.

Cromolyn sodium encapsulated PLGA nanoparticles: An attempt to improve intestinal permeation

High hydrophilicity curtails the intestinal permeation of cromolyn sodium (CS) which in turn compels to compromise with its multiple biological activities. Hence, the present research was intended with an objective to develop CS encapsulated polylactide-co-glycolide (PLGA) nanoparticles (CS-PNs) for enhancing intestinal permeation. The CS-PNs were prepared by double emulsification solvent evaporation method (W1/O/W2). The “Quality by Design” approach using box-behnken experimental design was employed to enhance encapsulation of CS inside CS-PNs without compromising with particle size. The polymer concentration, surfactant concentration and organic/aqueous phase ratio significantly affected the physicochemical properties of CS-PNs. The optimized CS-PNs were subjected to various solid-state and surface characterization studies using FTIR, DSC, XRD, TEM and AFM, which pointed towards the encapsulation of CS inside the spherical shaped nanoparticles without any physical as well as chemical interactions. Ex-vivo intestinal permeation study demonstrated ∼4 fold improvements in CS permeation by forming CS-PNs as compared to pure CS. Further, in-vivo intestinal uptake study performed using confocal microscopy, after oral administration confirmed the permeation potential of CS-PNs. Thus, the findings of the studies suggest that CS-PNs could provide a superior therapeutic carrier system of CS, with enhanced intestinal permeation.

Enhanced antitumor effects by docetaxel/LL37-loaded thermosensitive hydrogel nanoparticles in peritoneal carcinomatosis of colorectal cancer.

Intraperitoneal chemotherapy was explored in clinical trials as a promising strategy to improve the therapeutic effects of chemotherapy. In this work, we developed a biodegradable and injectable drug-delivery system by coencapsulation of docetaxel (Doc) and LL37 peptide polymeric nanoparticles (Doc+LL37 NPs) in a thermosensitive hydrogel system for colorectal peritoneal carcinoma therapy. Firstly, polylactic acid (PLA)-Pluronic L35-PLA (PLA-L35-PLA) was explored to prepare the biodegradable Doc+LL37 NPs using a water-in-oil-in-water double-emulsion solvent-evaporation method. Then, biodegradable and injectable thermosensitive PLA-L64-PLA hydrogel with lower sol–gel transition temperature at around body temperature was also prepared. Transmission electron microscopy revealed that the Doc+LL37 NPs formed with the PLA-L35-PLA copolymer were spherical. Fourier-transform infrared spectra certified that Doc and LL37 were encapsulated successfully. X-ray diffraction diagrams indicated that Doc was encapsulated amorphously. Intraperitoneal administration of Doc+LL37 NPs–hydrogel significantly suppressed the growth of HCT116 peritoneal carcinomatosis in vivo and prolonged the survival of tumor-bearing mice. Our results suggested that Doc+LL37 NPs–hydrogel may have potential clinical applications.

Tailoring sub-micron PLGA particle release profiles via centrifugal fractioning.

Poly(D,L-lactic-co -glycolic) acid (PLGA)-based sub-micron particles are uniquely posed to overcome limitations of conventional drug delivery systems. However, tailoring cargo/payload release profiles from PLGA micro/nanoparticles typically requires optimization of the multi-parameter formulation, where small changes may cause drastic shifts in the resulting release profiles. In this study, we aimed to establish whether refining the average diameter of sub-micron particle populations after formulation alters protein release profiles. PLGA particles were first produced via double emulsion-solvent evaporation method to encapsulate bovine serum albumin. Particles were then subjected to centrifugal fractioning protocols varying in both spin time and force to determine encapsulation efficiency and release profile of differently sized populations that originated from a single batch. We found the average particle diameter was related to marked alterations in encapsulation efficiencies (range: 36.4-49.4%), burst release (range: 15.8-49.1%), and time for total cargo release (range: 38-78 days). Our data corroborate previous reports relating PLGA particle size with such release characteristics, however, this is the first study, to our knowledge, to directly compare particle population size while holding all formulation parameters constant. In summary, centrifugal fractioning to selectively control the population distribution of sub-micron PLGA particles represents a feasible tool to tailor release characteristics. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part A 104A: 688-696, 2016.

Inhaled sildenafil nanocomposites: lung accumulation and pulmonary pharmacokinetics

Context: Administration of sildenafil citrate (SC) is considered as a strategy in the treatment of pulmonary hypertension.Objective: This study reports production of the inhalable microparticles containing SC-loaded poly(lactide-co-glycolic acid)-nanoparticles.Methods: SC-nanoparticles were prepared by the double emulsion solvent evaporation method. Next, free SC and SC-loaded nanoparticles were spray dried in the presence of appropriate excipients (lactose, maltose and trehalose). Physicochemical properties and aerodynamic behavior of prepared powders were evaluated. In addition, drug accumulation from selected formulations in the rat lung tissue was compared with oral and IV administration.Results: Size and fine particle fraction of selected nanocomposites and free SC microparticles were 7 and 4.5 µm, and 60.2% and 68.2%, respectively. Following oral and IV administration, the drug was not detectable in the lung after 4 and 6 h, respectively, but in SC-loaded nanoparticles, the drug was detectable in the lung even after 12 h of inhalation. Respirable particles containing free SC provided high concentration at first that was detectable up to 6 after insufflation.Conclusion: In vivo study demonstrated that pulmonary administration of sildenafil and sildenafil nanoparticles produced longer half-life and higher concentration of the drug in the lung tissue as compared to oral and IV administration. So, these formulations could be more effective than oral and IV administration of this drug.

Abstract 4396: Nanocarrier for monoclonal antibody delivery

Abstract Antibodies represent a large class of drugs that have a number of different therapeutic uses. The use of monoclonal antibodies against potential intracellular protein-protein interactions in cancer cells has remained largely unexplored. This lack of consideration is due largely to a number of factors that include poor intracellular uptake and rapid lysosomal degradation of monoclonal antibodies within cells. Encapsulating monoclonal antibodies within biodegradable nanoparticles is one strategy that can improve antibody cellular uptake and protect from lysosomal degradation so that the antibody can be released inside the cell and remain functional against the therapeutic target. Purpose: The purpose of this study is to characterize a human monoclonal antibody encapsulated within poly(lactic-co-glycolytic) acid (PLGA) nanoparticles. We hypothesized that encapsulation of an antibody within PLGA nanoparticles is feasible and will release in a favorable manner. Method: Anti-AnnexinA2 (AnxA2) monoclonal antibody was encapsulated within PLGA nanoparticles utilizing a water/oil/water double emulsion solvent evaporation method. Nanoparticles and released antibodies were characterized through a number of different modalities. Results: Our results show encapsulation efficiency ranging from 16-22% with a mean of 18.725% (SEM 1.289) depending on initial concentration of antibody used in the nanoparticle formulation. Nanoparticles were formed in a favorable mono disperse manner as evidenced through dynamic light scattering. All of the formulations created maintained a hydrodynamic size below 250nm. Release kinetics revealed that at day 12 the cumulative release of the antibody is approximately 35%. In addition after release the antibody maintained functionality as evidenced through Western Blot analysis and immunocytochemistry. Conclusions: Encapsulation of a monoclonal antibody within polymeric PLGA nanoparticles is feasible, exhibits sustained release kinetics, and maintains functionality upon release. This encapsulation technique may be used as a method to load antibodies in targeted nanoparticles and release the antibodies inside cancer cells to interfere with aberrantly expressed proteins. Future experiments will focus on utilizing this monoclonal antibody encapsulation approach to screen intracellular protein-protein interactions as potential new therapeutic cancer targets. Note: This abstract was not presented at the meeting. Citation Format: Andrew Gdowski, Amalendu Ranjan, Anindita Mukerjee, Jamboor Vishwanatha. Nanocarrier for monoclonal antibody delivery. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4396. doi:10.1158/1538-7445.AM2015-4396