Novel self-assembled core-shell nanoparticles based on crystalline amorphous moieties of aliphatic copolyesters for efficient controlled drug release

Kartogenin-loaded hydrogel promotes intervertebral disc repair via protecting MSCs against reactive oxygen species microenvironment by Nrf2/TXNIP/NLRP3 axis

Intervertebral disc (IVD) degeneration (IDD) and the consequent low back pain present a major medical challenge. Stem cell-based tissue engineering is promising for the treatment of IDD. However, stem cell-based treatment is severely impaired by the increased generation of reactive oxygen species (ROS) in degenerative disc, which can lead to a high level of cell dysfunction and even death. In this study, a kartogenin (KGN)@PLGA-GelMA/PRP composite hydrogel was designed and used as a carrier of ADSCs-based therapies in disc repair. Injectable composite hydrogel act as a carrier for controlled release of KGN and deliver ADSCs to the degenerative disc. The released KGN can stimulate the differentiation of ADSCs into a nucleus pulposus (NP) -like phenotype and boost antioxidant capacity of ADSCs via activating Nrf2/TXNIP/NLRP3 axis. Furthermore, the composite hydrogel combined with ADSCs attenuated the in vivo degeneration of rat IVDs, maintained IVD tissue integrity and accelerated the synthesis of NP-like extracellular matrix. Therefore, the KGN@PLGA-GelMA/PRP composite hydrogel is a promising strategy for stem cell-based therapies of IDD.

k-Carrageenan/sericin-based multiparticulate systems: A novel gastro-resistant polymer matrix for indomethacin delivery

This study aimed to develop a natural and multiparticulate carrier of k-carrageenan (k-Car) and sericin (Ser) for encapsulation of indomethacin (IND) in order to minimize gastrointestinal effects caused by immediate-release. Increasing the amount of IND in the formulations subtly reduced the entrapment efficiency (EE) and drug loading (DL) due to matrix saturation. Sericin was essential to improve EE and DL when compared to pure k-Car (EE > 90 % and DL > 47 %) with suitable particle sizes (1.3461 ± 0.1891-1.7213 ± 0.1586 mm). The incorporation and integrity of IND in the particles were confirmed by analytical techniques of HPLC, XRD, FTIR, and SEM. Additionally, the k-Car/Ser matrix was pH-responsive with low IND release at pH 1.2 and extended-release at pH 6.8. The Weibull model had an adequate fit to the experimental data with R²aju 0.950.99 and AIC 82.4-24.9, with curves in parabolic profile (b < 1) and indicative of a controlled drug-release mechanism by diffusion. Besides, k-Car/Ser/IND and placebo were not cytotoxic (cell viability > 85 % at 150-600 μM) for the Caco-2 cell line. Therefore, the polymeric matrix is gastro-resistant, stable, and biocompatible to carry indomethacin and deliver it to the intestinal environment.

Levofloxacin in nanostructured lipid carriers: Preformulation and critical process parameters for a highly incorporated formulation

The first step of a successful nanoformulation development is preformulation studies, in which the best excipients, drug-excipient compatibility and interactions can be identified. During the formulation, the critical process parameters and their impact must be studied to establish the stable system with a high drug entrapment efficiency (EE). This work followed these steps to develop nanostructured lipid carriers (NLCs) to deliver the antibiotic levofloxacin (LV). The preformulation studies covered drug solubility in excipients and thorough characterization using thermal analysis, X-ray diffraction and spectroscopy. A design of experiment based on the process parameters identified nanoparticles with < 200 nm in size, polydispersity <= 0.3, zeta potential -21 to -24 mV, high EE formulations (>71 %) and an acceptable level of LV degradation products (0.37-1.13 %). To the best of our knowledge, this is the first time that a drug degradation is reported and studied in work on nanostructured lipids. LV impurities following the NLC production were detected, mainly levofloxacin N-oxide, a degradation product that has no antimicrobial activity and could interfere with LV quantification in spectrophotometric experiments. Also, the achievement of the highest EE in lipid nanoparticles than those described in the literature to date and the apparent protective action of NLC of entrapped-LV against degradation are important findings.

Formulation of selenium nanoparticles encapsulated by alginate-chitosan for controlled delivery of Vibrio Cholerae LPS: A novel delivery system candidate for nanovaccine

The lipopolysaccharide (LPS) of Vibrio cholerae plays a significant role in stimulating primary protection and immune responses. LPS delivery has been limited by the stimulation of inflammatory cytokines. This work aimed to report the synthesis and performance of this formulation in modulating immune responses and protecting LPS against acidic gastric medium. Alg-Cs-LPS-SeNPs composite was fabricated by an ionic cross-linking/in situ reduction method. Cytokines TNF-α, IL-6, IL-10, and TGF-β were assessed after cells were incubated with different compounds of the system. The main outcomes revealed that encapsulation of LPS-loaded SeNPs in the alginate-chitosan complex was associated with a high entrapment efficiency and could effectively protect LPS against acidic GIT medium. Kinetic profiling revealed that LPS was more slowly released from LPS-loaded Alg-Cs-LPS-SeNPs at pH 1.2, 7.4, and 6.8. These results indicated that Alg-Cs-LPS-SeNPs composite was able to significantly increase anti-inflammatory cytokines and reduce the release of pro-inflammatory cytokines. Thus, these findings show that this system for LPS delivery could be easily biosynthesized and encapsulated for use in the pharmaceutical industry. This study provides proof of the potential for future use of oral LPS vaccines, concomitantly inducing immunomodulatory effects.

Resveratrol-loaded chitosan-pectin core-shell nanoparticles as novel drug delivery vehicle for sustained release and improved antioxidant activities

Resveratrol, chemically known as 3,5,4'-trihydroxy-trans-stilbene, is a natural polyphenol with promising multi-targeted health benefits. The optimal therapeutic uses of resveratrol are limited due to its poor solubility, rapid metabolism and low bioavailability. To address the issues, we have encapsulated resveratrol inside the nanosized core made of chitosan and coated this core with pectin-shell in order to fabricate a drug delivery vehicle which can entrap resveratrol for a longer period of time. The core-shell nanoparticles fabricated in this way were characterized with the help of Fourier transform infrared spectrometer, field-emission scanning electron microscope, field-emission transmission electron microscopy/selected area electron diffraction, high-resolution transmission electron microscope, dynamic light scattering and zeta potential measurements. In vitro drug release study showed the ability of the core-shell nanoparticles to provide sustained release of resveratrol for almost 30 h. The release efficiency of the drug was found to be pH dependent, and a sequential control over drug release can be obtained by varying the shell thickness. The resveratrol encapsulated in a nanocarrier was found to have a better in vitro antioxidant activity than free resveratrol as determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging method. This work finally offers a novel nano-based drug delivery system.

Development of a gliclazide ionic liquid and its mesoporous silica particles: an effective formulation strategy to improve oral absorption properties

Ionic liquid (IL) technology provides a useful platform to enhance the oral absorption of therapeutic agents. In the present work, gliclazide (GLI), a second-generation sulfonylurea drug was transformed into an IL with tetrabutylphosphonium. The physicochemical properties of this IL were systematically characterized by DSC, TGA, FT-IR, NMR, and HPLC. For the further preparation development, a solution stability test was conducted. GLI-based IL could improve the solution stability in a neutral environment. To assess oral potential, the solubility characteristics including equilibrium solubility, 24 h kinetic saturation solubilities and supersaturation profiles were first explored. Significant enhancement of solubilities, supersaturation ratio and duration of supersaturation was found for the synthesized IL. Computational methodology was utilized to better understand the improved solubility results. From the simulated results, [TBP][GLI] showed a longer time period when the distance between cation and anion was far above the baseline and a higher deviation degree, indicating less stable ion pairs of [TBP][GLI] in an aqueous environment and it being easy for the cation and anion to tear apart and form interactions with water molecules. The prepared [TBP][GLI] exhibited intestinal transportation ability and safety as evidenced by the in vitro gastrointestinal tract artificial membrane permeability assays (GIT-PAMPA) and cytotoxicity experiments with Caco-2 cells. A mesoporous carrier, AEROPERL® 300 Pharma, was chosen to load the IL and then encapsuled into enteric capsules. The prepared oral capsules containing GLI-based IL loaded mesoporous silica particles released fast and could realize 100% release within 60 min.

An ionic liquid (IL) form of gliclazide with enhanced solubility characteristics was successfully synthesized. This IL could be loaded into mesoporous silica carrier and exhibited improved dissolution behavior in vitro.

Double-Coated Poly(butyl Cyanoacrylate) Nanoparticles as a Potential Carrier for Overcoming P-Gp- and BCRP-Mediated Multidrug Resistance in Cancer Cells

The present study evaluates poly (butyl cyanoacrylate) nanoparticles (PBCA-NPs), double-coated with Tween 80 and polyethylene glycol (PEG) 20,000 as a potential carrier system for overcoming P-glycoprotein (P-gp) and breast cancer resistant protein (BCRP)-mediated multidrug resistance (MDR) in cancer cell lines. Doxorubicin-loaded PBCA-NPs were prepared by the anionic polymerization method and were successively double-coated with Tween 80 and PEG 20000 at varied concentrations. MDR reversing potential was investigated by cellular uptake in P-gp overexpressing cell line. And, the outcomes were verified by modified MTT assay in P-gp or BCRP overexpressing cell lines. The findings from the cell uptake study indicate that double-coated PBCA-NPs significantly enhanced doxorubicin accumulation within the cells. MTT assays revealed that double-coated PBCA-NPs significantly potentiated the sensitivity of doxorubicin in P-gp overexpressing cells, in comparison to free doxorubicin, single-, and un-coated PBCA-NPs, respectively. Moreover, further increase in concentration with Tween 80, double-coated PBCA-NPs significantly enhanced the sensitivity of doxorubicin in BCRP overexpressing cell line, in comparison to single- and double-coated formulations (with lower concentration of Tween 80). Hence, it could be concluded that double-coated PBCA-NPs can be used as a potential carrier for enhancing doxorubicin accumulation in MDR cancer cells.

Formulation, Optimization and Evaluation of Nanoparticulate Oral Fast Dissolving Film Dosage Form of Nitrendipine

The primary objective of the present research work was to develop nanoparticles incorporating (nanoparticulate) fast dissolving (orodispersible) film evincing enhanced solubility and bioavailability of nitrendipine (NIT). An antisolvent sonoprecipitation method was employed to produce the NIT nanosuspension (NS), which was optimized using the 3² optimal response surface design and then the optimized one was evaluated for various parameters (Gandhi et al., AAPS PharmSciTech 22 (1):1-15, 2021). The NIT nanoparticulate orodispersible film (N-ODF) was prepared utilizing the nanosuspension by the solvent casting method using the Vijay film-forming instrument. The N-ODF was optimized by the 2³ full factorial design and was evaluated for several parameters. The optimized NS depicted a particle size of 505.74 ± 15.48 nm with a polydispersity index (PDI) of 0.083 ± 0.006 (Fig. 1b). The NIT nanoparticles showed a striking increment in saturation solubility (26.14 times), when compared with plain NIT (2). The developed NIT N-ODF exhibited thickness (0.148 ± 0.008 mm), folding endurance (280.33 ± 5.51 times), surface pH (6.86 ± 0.05), tensile strength (8.25 ± 0.13 kg/cm²), % elongation (63.5 ± 1.97%), and disintegration time (24.60 ± 1.31 s) to be within the standard intended limit. The in vitro dissolution study unveiled 100.28 ± 2.64% and 100.68 ± 2.50% of NIT release from lyophilized nanocrystals (in 8 min) and N-ODF (in 3.5 min), respectively, whereas the conventional NIT tablet took 30 min to release 99.94 ± 1.57% of NIT (Gandhi et al., AAPS PharmSciTech 22 (1):1-15, 2021). The in vivo pharmacokinetic study in rabbits inferred the achievement of significantly (p < 0.05) higher bioavailability of NIT on release from N-ODF in comparison to the conventional NIT tablet. Thus, the generation of N-ODF can be considered as a propitious move toward improving the efficacy of NIT to treat hypertension and angina pectoris.

Oral Delivery of Nucleic Acids with Passive and Active Targeting to the Intestinal Tissue Using Polymer-Based Nanocarriers

Despite the apparent advantages for long-term treatment and local therapies against intestinal diseases, the oral delivery of nucleic acids has been challenging due to unfavorable physiological conditions for their stability. In this study, a novel nanodelivery system of PEG-PCL nanoparticles with encapsulated nucleic acids–mannosylated PEI (Man-PEI) complexes was developed for intestinal delivery. We complexed model nucleic acids with Man-PEI at the optimal N/P ratio of 20:1 for in vitro and in vivo analyses. Cells were transfected in vitro and analyzed for gene expression, receptor-mediated uptake, and PEG-PCL nanoparticles’ toxicity. We also evaluated the nucleic acid’s stability in the nanocarrier during formulation, and under simulated gastrointestinal environments or the presence of nucleases. Finally, we assessed the biodistribution for the PEG-PCL nanoparticles with encapsulated complexes and their ability to transfect intestinal cells in vivo. Nucleic acids complexed with Man-PEI were protected from degradation against nucleases. In comparison to the parent compound PEI, Man-PEI transfected the cells with an overall higher potency. Competition assay indicated receptor-mediated endocytosis promoted by mannose receptors. The PEG-PCL nanoparticles with Man-PEI/plasmid complexes indicated minimal cytotoxicity. The nanocarrier successfully protected the complexes in a simulated gastric fluid environment and released them in a simulated intestinal fluid environment, promoted by the presence of lipases. The oral administration of the PEG-PCL nanoparticles with encapsulated Man-PEI/plasmid complexes transfected intestinal cells with the plasmid in vivo, while presenting a time-dependent progression through the intestines. Conclusively, our carrier system can deliver genetic material to the GI tract and actively target mannose receptor overexpressing cells.

Novel dental implant modifications with two-staged double benefits for preventing infection and promoting osseointegration in vivo and in vitro

Peri-implantitis are a major problem causing implant failure these days. Accordingly, anti-infection during the early stage and subsequent promotion of osseointegration are two main key factors to solve this issue. Micro-arc oxidation (MAO) treatment is a way to form an oxidation film on the surface of metallic materials. The method shows good osteogenic properties but weak antibacterial effect. Therefore, we developed combined strategies to combat severe peri-implantitis, which included the use of a novel compound, PD, comprising dendrimers poly(amidoamine) (PAMAM) loading dimethylaminododecyl methacrylate (DMADDM) as well as MAO treatment. Here, we explored the chemical properties of the novel compound PD, and proved that this compound was successfully synthesized, with the loading efficiency and encapsulation efficiency of 23.91% and 31.42%, respectively. We further report the two-stage double benefits capability of PD + MAO: (1) in the first stage, PD + MAO could decrease the adherence and development of biofilms by releasing DMADDM in the highly infected first stage after implant surgery both in vitro and in vivo; (2) in the second stage, PD + MAO indicated mighty anti-infection and osteoconductive characteristics in a rat model of peri-implantitis in vivo. This study first reports the two-staged, double benefits of PD + MAO, and demonstrates its potential in clinical applications for inhibiting peri-implantitis, especially in patients with severe infection risk.

Alginate sulfate-based hydrogel/nanofiber composite scaffold with controlled Kartogenin delivery for tissue engineering

In this study, we fabricated two different arrangements of laminated composite scaffolds based on Alginate:Alginate sulfate hydrogel, PCL:Gelatin electrospun mat, and Kartogenin-PLGA nanoparticles (KGN-NPs). The optimized composite scaffold revealed a range of advantages such as improved mechanical features as well as less potential of damage (less dissipated energy), interconnected pores of hydrogel and fiber with adequate pore size, excellent swelling ratio, and controlled biodegradability. Furthermore, the synthesized KGN-NPs with spherical morphology were incorporated into the composite scaffold and exhibited a linear and sustained release of KGN within 30 days with desirable initial burst reduction (12% vs. 20%). Additionally, the cytotoxicity impact of the composite was evaluated. Resazurin assay and Live/Dead staining revealed that the optimized composite scaffold has no cytotoxic effect and could improve cell growth. Overall, according to the enhanced mechanical features, suitable environment for cellular growth, and sustained drug release, the optimized scaffold would be a good candidate for tissue regeneration.

Development of Nanonized Nitrendipine and Its Transformation into Nanoparticulate Oral Fast Dissolving Drug Delivery System

The present research focuses on the development of a nanoparticulate (nanocrystals-loaded) rapidly dissolving (orodispersible) tablet with improved solubility and bioavailability. The nanosuspension (NS) was prepared by antisolvent sonoprecipitation technique and the optimized NS was lyophilized to obtain nanocrystals (NCs), which were evaluated for various parameters. The nitrendipine (NIT) nanoparticulate orodispersible tablet (N-ODT) was prepared by direct compression method. The optimized N-ODT was evaluated for pre and post compression characteristics, in vivo pharmacokinetic and stability profile. The optimized NS showed a particle size of 505.74 ± 15.48 nm with a polydispersity index (PDI) of 0.083 ± 0.006. The % NIT content in the NCs was found to be 78.4 ± 2.3%. The saturation solubility of NIT was increased remarkably (26.14 times) in comparison to plain NIT, post NCs development. The DSC and p-XRD analysis of NCs revealed the perseverance of the integrity and crystallinity of NIT on lyophilization. The results of micromeritic studies revealed the good flow-ability and compressibility of NCs blend. All the post-compression properties of N-ODT were observed within the standard intended limit. The dispersion, wetting, and disintegration time of the optimized batch of N-ODT was found to be 39 ± 1.13 s, 44.66 ± 1.52 s, and 33.91 ± 0.94 s respectively. The in vitro dissolution study displayed 100.28 ± 2.64% and 100.61 ± 3.3% of NIT released from NCs (in 8 min) and N-ODT (in 6 min) respectively, while conventional NIT tablet took 30 min to release 99.94 ± 1.57% of NIT. The in vivo pharmacokinetic study in rabbits demonstrated significantly (p < 0.05) higher bioavailability of NIT on release from N-ODT than the conventional NIT tablet. Thus, N-ODT could be a promising tool for improving the solubility and bioavailability of NIT and to treat cardiovascular diseases effectively.

Development of L-carnosine functionalized iron oxide nanoparticles loaded with dexamethasone for simultaneous therapeutic potential of blood brain barrier crossing and ischemic stroke treatment

The development of suitable drug delivery carriers is significant in biomedical applications to improve the therapeutic efficiency. Recent progress in nanotechnological fields, paved the way for the formulation of variety of drug carriers. The brain disorders such as ischemic stroke, brain cancer, and CNS disorders were poorly treated due to the presence of blood brain barrier that hinders the passage of drugs to the brain. Hence, the formulated drugs should have the ability to cross the blood-brain barrier (BBB) for ischemic stroke treatment. In the present work, we have synthesized PLGA functionalized magnetic Fe₃O₄ nanoparticle (MNP) with L-carnosine peptide (LMNP) composite loaded with dexamethasone (dm@LMNP) and demonstrated as efficient drug delivery platform for simultaneous BBB crossing and treatment of ischemic stroke. The surface morphology, particles size and zeta potential of the prepared material was studied from SEM, PSD, PDI and TEM analyses. The drug loading of dexamethasone in LMNP (dm@LMNP) vesicles was found to be 95.6 ± 0.2%. The in vitro drug release kinetics displayed that prepared composited LMNP material provides controlled and sustainable releasing efficiency at pH 7.4 and 5.8 when compared to the PLGA NPs and free dexamethasone drug molecules. The cytotoxicity and the biocompatibility test results were found to be satisfactory. The L-carnosine loaded nano-formulation has been greatly leads to effective BBB crossing to access the brain tissues. These results showed that the Fe₃O₄ nanoparticles/PLGA polymer can be used as an effective drug carrier for the treatment of stroke and simultaneous blood brain barrier crossing.

Microfluidic-assisted nanoprecipitation of biodegradable nanoparticles composed of PTMC/PCL (co)polymers, tannic acid and doxorubicin for cancer treatment

This study was aimed towards the development of a novel microfluidic approach for the preparation of (co)polymeric and hybrid nanoparticles (NPs) composed of (co)polymers/tannic acid (TA) in the microfluidic flow-focusing glass-capillary device. The MiliQ water was used as water phase, whereas the organic phase was composed of poly(ε-caprolactone) (PCL) and poly(trimethylene carbonate) (PTMC) homopolymers and (co)polymers with different proportion of comonomers which were prepared via enzymatic polymerization that allows avoiding the usage of potentially toxic catalyst. To prepare hybrid NPs, TA was additionally added to the organic phase. Subsequently, as a result of mixing between these distinct phases in microfluidic channels, the nanoprecipitation in the form of spherical NPs occurs. The size of NPs was tuned over the range of 140-230 nm by controlling phase flow rates and the composition of NPs. Moreover, the release studies of the encapsulated anticancer drug doxorubicin (DOX) demonstrated that the drug release is greatly influenced by the (co)polymers composition, their molecular weight, NPs size, and the presence of TA. The antitumor activities of the (co)polymeric and hybrid NPs toward breast cancer cells (MCF-7) were tested in vitro. Among all tested formulation, the NPs composed of PCL/TA most efficiently inhibit the cell proliferation of MCF-7 cells, most importantly, their efficiency was higher than free DOX. The proposed strategy may provide an efficient alternative for the construction of nanocarriers with great potential in anticancer therapy.

Dissolution Enhancement and Controlled Release of Paclitaxel Drug via a Hybrid Nanocarrier Based on mPEG-PCL Amphiphilic Copolymer and Fe-BTC Porous Metal-Organic Framework

In the present work, the porous metal-organic framework (MOF) Basolite®F300 (Fe-BTC) was tested as a potential drug-releasing depot to enhance the solubility of the anticancer drug paclitaxel (PTX) and to prepare controlled release formulations after its encapsulation in amphiphilic methoxy poly(ethylene glycol)-poly(ε-caprolactone) (mPEG-PCL) nanoparticles. Investigation revealed that drug adsorption in Fe-BTC reached approximately 40%, a relatively high level, and also led to an overall drug amorphization as confirmed by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The dissolution rate of PTX-loaded MOF was substantially enhanced achieving a complete (100%) release within four days, while the neat drug only reached a 13% maximum rate (3-4 days). This PTX-Fe-BTC nanocomposite was further encapsulated into a mPEG-PCL matrix, a typical aliphatic amphiphilic copolyester synthesized in our lab, whose biocompatibility was validated by in vitro cytotoxicity tests toward human umbilical vein endothelial cells (HUVEC). Encapsulation was performed according to the solid-in-oil-in-water emulsion/solvent evaporation technique, resulting in nanoparticles of about 143 nm, slightly larger of those prepared without the pre-adsorption of PTX on Fe-BTC (138 nm, respectively). Transmission electron microscopy (TEM) imaging revealed that spherical nanoparticles with embedded PTX-loaded Fe-BTC nanoparticles were indeed fabricated, with sizes ranging from 80 to 150 nm. Regions of the composite Fe-BTC-PTX system in the infrared (IR) spectrum are identified as signatures of the drug-MOF interaction. The dissolution profiles of all nanoparticles showed an initial burst release, attributed to the drug amount located at the nanoparticles surface or close to it, followed by a steadily and controlled release. This is corroborated by computational analysis that reveals that PTX attaches effectively to Fe-BTC building blocks, but its relatively large size limits diffusion through crystalline regions of Fe-BTC. The dissolution behaviour can be described through a bimodal diffusivity model. The nanoparticles studied could serve as potential chemotherapeutic candidates for PTX delivery.

Nano-ellagic acid: inhibitory actions on aldose reductase and α-glucosidase in secondary complications of diabetes, strengthened by in silico docking studies

Increased blood sugar levels in prolonged diabetes lead to secondary complications such as retinopathy, neuropathy, and nephropathy, which gradually end in death. Synthesis of nano-phytomedicines from active phytoconstituents for novel emerging applications in the field of pharmaceuticals is of huge interest among researchers. In the present investigation, encapsulated ellagic acid (NEA) was synthesized at four different concentrations (0.2%, 0.3%, 0.4%, 0.5%) using ZnO nanoparticles as encapsulating agent. The surface morphology (fiber-like structures) of the nanoparticles were determined by scanning electron microscopy (SEM) and particle size (161-297 nm) and zeta potential (- 54.9-38.4 mV) were determined by dynamic light scattering technique. Further, the α-glucosidase and aldose reductase enzymes were significantly inhibited by the 0.4% of NEA compared to the other concentrations which strengthened our studies in overcoming the secondary complications of diabetes. The interaction analysis between ellagic acid and insulin receptor found Hit 1 among 10 executed ∆G score and energy of - 5.76, - 4.63 kcal/mol and formed polar bond with Arg 113 with - 1.175 Å distance. The residues Arg115, Lys116, Phe118, Ile115, Arg1131, Arg1155, Ile1157, Lys1165 and Phe1186 were found in ligand-protein interactions. ADME/T analysis of hit 1 was within the acceptable range without any toxic functional groups, providing a framework for developing novel therapeutics.

Formulation and optimization of quinoa starch nanoparticles: Quality by design approach for solubility enhancement of piroxicam

In the present study piroxicam loaded starch nanoparticles were prepared to enhance the solubility of piroxicam by nanoprecipitation technique. The preparation of nanoparticles was carried out as per central composite experimental design protocol, having concentration of starch and drug as independent variables and particle size and polydispersity index (PdI) as dependent variables. The particle size and PdI of piroxicam loaded starch nanoparticles was found to be between 282–870 nm and 0.339–0.772, respectively. After the characterization by FT-IR, TGA, XRD and SEM studies, the optimized batch was evaluated for in-vitro release study, anti-inflammatory activity and anti-oxidant activity. The in-vitro anti-inflammatory activity of piroxicam loaded starch nanoparticles was found to be more than the pure drug piroxicam whereas the anti-oxidant activity of starch is found greater than starch nanoparticles. In-vitro release study showed 98.8% release in 2 h dissolution study following supercase II transport mechanism of drug release.

Long acting anti-infection constructs on titanium

Peri-prosthetic joint infections (PJI) are a serious adverse event following joint replacement surgeries; antibiotics are usually added to bone cement to prevent infection offset. For uncemented prosthesis, alternative antimicrobial approaches are necessary in order to prevent PJI; however, despite elution of drug from the surface of the device being shown one of the most promising approach, no effective antimicrobial eluting uncemented device is currently available on the market. Consequently, there is a clinical need for non-antibiotic antimicrobial uncemented prosthesis as these devices present numerous benefits, particularly for young patients, over cemented artificial joints. Moreover, non-antibiotic approaches are driven by the need to address the growing threat posed by antibiotic resistance. We developed a multilayers functional coating on titanium surfaces releasing chlorhexidine, a well-known antimicrobial agent used in mouthwash products and antiseptic creams, embedding the drug between alginate and poly-beta-amino-esters. Chlorhexidine release was sustained for almost 2 months and the material efficacy and safety was proven both in vitro and in vivo. The coatings did not negatively impact osteoblast and fibroblast cells growth and were capable of reducing bacterial load and accelerating wound healing in an excisional wound model. As PJI can develop weeks and months after the initial surgery, these materials could provide a viable solution to prevent infections after arthroplasty in uncemented prosthetic devices and, simultaneously, help the fight against antibiotic resistance.

Codelivery of STAT3 siRNA and BV6 by carboxymethyl dextran trimethyl chitosan nanoparticles suppresses cancer cell progression

High expression of inhibitor of apoptosis (IAP) molecules in cancer cells promotes cancer cell chemoresistance. Use of BV6, a well-known IAP inhibitor, along with inhibition of signal transducer and activator of transcription 3 (STAT3), which is an important factor in the survival of tumor cells, and NIK as a mediator of BV6 unpredicted side effects, can induce effective apoptosis in tumor cells. The present study has investigated the combination therapy of cancer cells using Carboxymethyl Dextran-conjugated trimethyl chitosan (TMC-CMD) nanoparticles (NPs) loaded with NIK/STAT3-specific siRNA and BV6 to synergistically induce apoptosis in the breast, colorectal and melanoma cancer cell lines. Our results showed that in addition to enhanced pro-apoptotic effects, this combination therapy reduced proliferation, cell migration, colony formation, and angiogenesis, along with expression of factors including IL-10 and HIF in tumor cells. The results indicate the potential of this combination therapy for further investigation in animal models of cancer.

Anticancer efficacy of 6-thioguanine loaded chitosan nanoparticles with or without curcumin

6-Thioguanine encapsulated chitosan nanoparticles (6-TG-CNPs) has formulated by the ionic-gelation method. Morphologically, the 6-TG-CNPs were spherical and showed mean size, PDI, zeta potential, and entrapment efficiency of 261.63 ± 6.01 nm, 0.34 ± 0.10, +15.97 ± 0.46 mV and 44.27%, respectively. The IR spectra confirmed the 6-TG complex with chitosan. The in vitro drug release profile of 6-TG-CNPs revealed an increase in sustained-release (91.40 ± 1.08% at 48 h) at pH 4.8 compared to less sustained-release (73.96 ± 1.12% at 48 h) at pH 7.4. The MTT assay was conducted on MCF-7 and PA-1 cell lines at 48 h incubation to determine % cell viability. The IC₅₀ values of 6-TG, 6-TG-CNPs, and curcumin for MCF-7 were 23.09, 17.82, and 15.73 μM, respectively. Likewise, IC₅₀ values of 6-TG, 6-TG-CNPs, and curcumin for PA-1 were 5.81, 3.92, and 12.89 μM, respectively. A combination of 6-TG-CNPs (IC₂₅) with curcumin (IC₂₅) on PA-1 and MCF-7 showed % cell viability of 43.67 ± 0.02 and 49.77 ± 0.05, respectively. The in vitro cytotoxicity potential in terms of % cell viability, early apoptosis, G2/M phase arrest, and DNA demethylating activity of 6-TG-CNPs alone and combination with curcumin proved to be more effective than that of 6-TG on PA-1 cells.

Nanoformulation-by-design: an experimental and molecular dynamics study for polymer coated drug nanoparticles

Experimental studies of drug–polymer nanoparticle formation combined with molecular dynamics simulations provide atomistic explanations for the high drug loadings obtained.

Enhancement in Site-Specific Delivery of Carvacrol against Methicillin Resistant Staphylococcus aureus Induced Skin Infections Using Enzyme Responsive Nanoparticles: A Proof of Concept Study

Methicillin resistant Staphylococcus aureus (MRSA) induced skin infections have become a challenging problem due to the escalating antibiotic resistance. Carvacrol (CAR) has been reported to be effective against MRSA. However, due to its characteristics, CAR exhibits low skin retention. In this study, CAR was formulated into site-specific nanoparticle (NPs) delivery system using poly(ε-caprolactone) (PCL), following incorporation into a hydrogel matrix to facilitate dermal delivery. The release study exhibited significantly higher release of CAR from PCL NPs in the presence of bacterial lipase, highlighting its potential for differential delivery. Moreover, encapsulation of CAR in PCL NPs resulted in a two-fold increase in its anti-MRSA activity. Dermatokinetic studies revealed that the NPs loaded hydrogel was able to enhance skin retention of CAR after 24 h (83.29 ± 3.15%), compared to free CAR-loaded hydrogel (0.85 ± 0.14%). Importantly, this novel approach exhibited effective antimicrobial activity in an ex-vivo skin infection model. Hence, these findings have proven the concept that the loading of CAR into a responsive NPs system can lead to sustained antimicrobial effect at the desired site, and may provide a novel effective approach for treatment of MRSA induced skin infections. However, further studies must be conducted to investigate in-vivo efficacy of the developed system in an appropriate infection model.

Formulation and optimization of drug-loaded mesoporous silica nanoparticle-based tablets to improve the dissolution rate of the poorly water-soluble drug silymarin

Porous carriers have been put forward as a promising alternative for stabilizing the amorphous state of loaded drugs, and thus significantly improving the dissolution rate of poorly soluble compounds. The purpose of this study was to enhance the saturation solubility, dissolution rate and drug loading of the poorly water-soluble drug silymarin via incorporation into mesoporous silica nanospheres within a lyophilized tablet to obtain a unique formulation. 3² full factorial design was applied to study the effect of both independent variables, polyvinyl alcohol (PVA) as stabilizer and binder and sucrose as cryoprotectant and disintegrant; and on the dependent variables that included the mean particle size (Y₁), disintegration time (Y₂), tablet strength (Y₃) and % of drug release after 2 min, R_2min,Y₄. The drug-loaded mesoporous silica nanospheres and the optimized formula was evaluated by different characterization methods: scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry, X-ray diffractometry and Fourier transform infrared spectroscopy; as well as drug content, saturation solubility and moisture content. The evaluation demonstrated that the loaded mesoporous silica nanospheres and the optimized formula are in amorphous state without any chemical interaction with the silica matrix or the stabilizer. Moreover, the drug was stably maintained in nanosize range with narrow particle size distribution. Furthermore, the optimized lyophilized tablets had highly porous structure, low friability (less than 1%), fast disintegration (less than 30 s), high tablet strength, low moisture content (less than 1%), remarkably increased dissolution rate and noticeable improvement in saturation solubility.

The comparison between superparamagnetic and ferromagnetic iron oxide nanoparticles for cancer nanotherapy in the magnetic resonance system

The paper aims to compare zeta potentials, magnetic properties, electron spin resonance, photoluminescence (PL) spectra and antitumor effect of magneto-mechano-chemically synthesized magneto-sensitive nanocomplexes loaded with the anticancer drug doxorubicin (DOXO) during nanotherapy of Walker-256 carcinosarcoma carried out by a magnetic resonance system. Diamagnetic DOXO acquired the properties of a paramagnetic substance after synthesis. MNC comprising superparamagnetic nanoparticles (NP) and DOXO had different g-factors, zeta potentials, a lower saturation magnetic moment, area of the hysteresis loop, and a higher coercivity compared to similar MNC with ferromagnetic NP. The main PL peak of MNC spectrum was defined by DOXO at 598 nm. MNC composed of superparamagnetic NP and DOXO showed a lower standard deviation of the normal PL spectral distribution than MNC based on ferromagnetic NP in relation to conventional DOXO. MNC containing superparamagnetic NP responded to resonance conditions leading to a more pronounced antitumor effect compared to MNC with ferromagnetic NP in the course of magnetic nanotherapy for Walker-256 carcinosarcoma bearing animals (temperature inside the tumor did not exceed 40 °C). Therefore, these findings are associated with differences in chemotherapeutic effect between MNC due to a different surface charge and conformational changes in DOXO molecules during its magnetoelectric interaction with single- and multidomain NP.

Bioinspired Liposomes for Oral Delivery of Colistin to Combat Intracellular Infections by Salmonella enterica

Bacterial invasion into eukaryotic cells and the establishment of intracellular infection has proven to be an effective means of resisting antibiotic action, as anti-infective agents commonly exhibit a poor permeability across the host cell membrane. Encapsulation of anti-infectives into nanoscaled delivery systems, such as liposomes, is shown to result in an enhancement of intracellular delivery. The aim of the current work is, therefore, to formulate colistin, a poorly permeable anti-infective, into liposomes suitable for oral delivery, and to functionalize these carriers with a bacteria-derived invasive moiety to enhance their intracellular delivery. Different combinations of phospholipids and cholesterol are explored to optimize liposomal drug encapsulation and stability in biorelevant media. These liposomes are then surface-functionalized with extracellular adherence protein (Eap), derived from Staphylococcus aureus. Treatment of HEp-2 and Caco-2 cells infected with Salmonella enterica using colistin-containing, Eap-functionalized liposomes resulted in a significant reduction of intracellular bacteria, in comparison to treatment with nonfunctionalized liposomes as well as colistin alone. This indicates that such bio-invasive carriers are able to facilitate intracellular delivery of colistin, as necessary for intracellular anti-infective activity. The developed Eap-functionalized liposomes, therefore, present a promising strategy for improving the therapy of intracellular infections.

Pharmacokinetics, Biodistribution, and Anti-Angiogenesis Efficacy of Diamino Propane Tetraiodothyroacetic Acid-conjugated Biodegradable Polymeric Nanoparticle

The anti-angiogenic agent, diamino propane tetraiodothyroacetic acid (DAT), is a thyro-integrin (integrin αvβ3) antagonist anticancer agent that works via genetic and nongenetic actions. Tetraiodothyroacetic acid (tetrac) and DAT as thyroid hormone derivatives influence gene expression after they transport across cellular membranes. To restrict the action of DAT to the integrin αvβ3 receptors on the cell surface, we used DAT-conjugated PLGA nanoparticles (NDAT) in an active targeting mode to bind to these receptors. Preparation and characterization of NDAT is described, and both in vitro and in vivo experiments were done to compare DAT to NDAT. Intracellular uptake and distribution of DAT and NDAT in U87 glioblastoma cells were evaluated using confocal microscopy and showed that DAT reached the nucleus, but NDAT was restricted from the nucleus. Pharmacokinetic studies using LC-MS/MS analysis in male C57BL/6 mice showed that administration of NDAT improved the area under the drug concentration curve AUC(0-48 h) by 4-fold at a dose of 3 mg/kg when compared with DAT, and Cmax of NDAT (4363 ng/mL) was 8-fold greater than that of DAT (548 ng/mL). Biodistribution studies in the mice showed that the concentrations of NDAT were higher than DAT/Cremophor EL micelles in heart, lung, liver, spleen, and kidney. In another mouse model using female NCr nude homozygous mice with U87 xenografts, tumor growth was significantly decreased at doses of 1 and 3 mg/kg of NDAT. In the chick chorioallantoic membrane (CAM) assay used to measure angiogenesis, DAT (500 ng/CAM) resulted in 48% inhibition of angiogenesis levels. In comparison, NDAT at low dose (50 ng/CAM) showed 45% inhibition of angiogenesis levels. Our investigation of NDAT bridges the study of polymeric nanoparticles and anti-angiogenic agents and offers new insight for the rational design of anti-angiogenic agents.

Use of nPSi-βCD Composite Microparticles for the Controlled Release of Caffeic Acid and Pinocembrin, Two Main Polyphenolic Compounds Found in a Chilean Propolis

Propolis is widely recognized for its various therapeutic properties. These are attributed to its rich composition in polyphenols, which exhibit multiple biological properties (e.g., antioxidant, anti-inflammatory, anti-angiogenic). Despite its multiple benefits, oral administration of polyphenols results in low bioavailability at the action site. An alternative to face this problem is the use of biomaterials at nano-micro scale due to its high versatility as carriers and delivery systems of various drugs and biomolecules. The aim of this work is to determine if nPSi-βCD microparticles are a suitable material for the load and controlled release of caffeic acid (CA) and pinocembrin (Pin), two of the main components of a Chilean propolis with anti-atherogenic and anti-angiogenic activity. Polyphenols and nPSi-βCD microparticles cytocompatibility studies were carried out with human umbilical vein endothelial cells (HUVECs). Results from physicochemical characterization demonstrated nPSi-βCD microparticles successfully retained and controlled release CA and Pin. Furthermore, nPSi-βCD microparticles presented cytocompatibility with HUVECs culture at concentrations of 0.25 mg/mL. These results suggest that nPSi-βCD microparticles could safely be used as an alternate oral delivery system to improve controlled release and bioavailability of CA or Pin-and eventually other polyphenols-thus enhancing its therapeutic effect for the treatment of different diseases.

Design of Poly(lactic-co-glycolic Acid) (PLGA) Nanoparticles for Vaginal Co-Delivery of Griffithsin and Dapivirine and Their Synergistic Effect for HIV Prophylaxis

Long-acting topical products for pre-exposure prophylaxis (PrEP) that combine antiretrovirals (ARVs) inhibiting initial stages of infection are highly promising for prevention of HIV sexual transmission. We fabricated core-shell poly(lactide-co-glycolide) (PLGA) nanoparticles, loaded with two potent ARVs, griffithsin (GRFT) and dapivirine (DPV), having different physicochemical properties and specifically targeting the fusion and reverse transcription steps of HIV replication, as a potential long-acting microbicide product. The nanoparticles were evaluated for particle size and zeta potential, drug release, cytotoxicity, cellular uptake and in vitro bioactivity. PLGA nanoparticles, with diameter around 180–200 nm, successfully encapsulated GRFT (45% of initially added) and DPV (70%). Both drugs showed a biphasic release with initial burst phase followed by a sustained release phase. GRFT and DPV nanoparticles were non-toxic and maintained bioactivity (IC₅₀ values of 0.5 nM and 4.7 nM, respectively) in a cell-based assay. The combination of drugs in both unformulated and encapsulated in nanoparticles showed strong synergistic drug activity at 1:1 ratio of IC₅₀ values. This is the first study to co-deliver a protein (GRFT) and a hydrophobic small molecule (DPV) in PLGA nanoparticles as microbicides. Our findings demonstrate that the combination of GRFT and DPV in nanoparticles is highly potent and possess properties critical to the design of a sustained release microbicide.

Formulation and Characterization of New Polymeric Systems Based on Chitosan and Xanthine Derivatives with Thiazolidin-4-One Scaffold

In the past many research studies have focused on the thiazolidine-4-one scaffold, due to the important biological effects associated with its heterocycle. This scaffold is present in the structure of many synthetic compounds, which showed significant biological effects such as antimicrobial, antifungal, antioxidant, anti-inflammatory, analgesic, antidiabetic effects. It was also identified in natural compounds, such as actithiazic acid, isolated from Streptomyces strains. Starting from this scaffold new xanthine derivatives have been synthetized and evaluated for their antibacterial and antifungal effects. The antibacterial action was investigated against Gram positive (Staphyloccoccus aureus ATCC 25923, Sarcina lutea ATCC 9341) and Gram negative (Escherichia coli ATCC 25922) bacterial strains. The antifungal potential was investigated against Candida spp. (Candida albicans ATCC 10231, Candida glabrata ATCC MYA 2950, Candida parapsilosis ATCC 22019). In order to improve the antimicrobial activity, the most active xanthine derivatives with thiazolidine-4-one scaffold (XTDs: 6c, 6e, 6f, 6k) were included in a chitosan based polymeric matrix (CS). The developed polymeric systems (CS-XTDs) were characterized in terms of morphological (aspect, particle size), physic-chemical properties (swelling degree), antibacterial and antifungal activities, toxicity, and biological functions (bioactive compounds loading, entrapment efficiency). The presence of xanthine-thiazolidine-4-one derivatives into the chitosan matrix was confirmed using Fourier transform infrared (FT-IR) analysis. The size of developed polymeric systems, CS-XTDs, ranged between 614 µm and 855 µm, in a dry state. The XTDs were encapsulated into the chitosan matrix with very good loading efficiency, the highest entrapment efficiency being recorded for CS-6k, which ranged between 87.86 ± 1.25% and 93.91 ± 1.41%, depending of the concentration of 6k. The CS-XTDs systems showed an improved antimicrobial effect with respect to the corresponding XTDs. Good results were obtained for CS-6f, for which the effects on Staphylococcus aureus ATCC 25923 (21.2 ± 0.43 mm) and Sarcina lutea ATCC 9341 (25.1 ± 0.28 mm) were comparable with those of ciprofloxacin (25.1 ± 0.08 mm/25.0 ± 0.1 mm), which were used as the control. The CS-6f showed a notable antifungal effect, especially on Candida parapsilosis ATCC 22019 (18.4 ± 0.42 mm), the effect being comparable to those of nystatin (20.1 ± 0.09 mm), used as the control. Based on the obtained results these polymeric systems, consisting of thiazolidine-4-one derivatives loaded with chitosan microparticles, could have important applications in the food field as multifunctional (antimicrobial, antifungal, antioxidant) packaging materials.

Dual-functionalised shellac nanocarriers give a super-boost of the antimicrobial action of berberine

We have developed highly efficient antimicrobial nanocarriers for berberine (BRB) based on shellac nanoparticles (NPs) which were surface-functionalised with a surface active polymer, Poloxamer 407 (P407), and the cationic surfactant octadecyltrimethylammonium bromide (ODTAB). These shellac nanocarriers were produced in a two-step process which involves: (i) a pH change from aqueous ammonium shellac solution using P407 as a steric stabilizer in the presence of berberine chloride, and (ii) addition of ODTAB to yield shellac nanocarriers of cationic surface. We determined the BRB encapsulation efficiency and release profiles from such nanocarriers. We explored the antimicrobial action of these nanocarriers at different stages of their preparation which allowed us gain better understanding how they work, fine tune their design and reveal the impact of the nanoparticle coatings on to its antimicrobial effect. The antimicrobial action of BRB loaded within such shellac NPs with cationic surface functionality was examined on three different microorganisms, C. reinhardtii, S. cerevisiae and E. coli and compared with the effect of free BRB as well as non-coated BRB-loaded nanocarriers at the same BRB concentrations. We found that the cationic surface coating of the shellac NPs strongly amplified the efficiency of the encapsulated BRB across all tested microorganisms. The effect was attributed to the increased attraction between the ODTAB-coated BRB-loaded NPs and the anionic surface of the cell walls which delivers locally high BRB concentration. This nanotechnological approach could lead to more effective antimicrobial and disinfecting agents, dental formulations for plaque control, wound dressings, antialgal/antibiofouling formulations and antifungal agents.

Antifungal efficacy of Itraconazole loaded PLGA-nanoparticles stabilized by vitamin-E TPGS: In vitro and ex vivo studies

Itraconazole (ITZ) loaded Poly-(D, L-lactic-co-glycolic acid, PLGA) nanoparticles (PLGA-NPs) stabilized by D-α-Tocopherol polyethylene-glycol succinate-1000 (TPGS) were developed by nanoprecipitation and single emulsion solvent evaporation methods to improve antifungal activity of ITZ by enhancing its solubility, and hence bioavailability. Encapsulation efficiency, drug loading, in-vitro release, ex-vivo permeation and antifungal activity were performed for the optimized PLGA-NPs. Characterization of PLGA-NPs were performed by scanning electron microscopy, dynamic light scattering, differential scanning calorimetry, Fourier transform infrared spectroscopy, and powder X-ray diffractometry. We observed that nanoprecipitation method was more efficient in encapsulating ITZ by using 0.3% TPGS (stabilizer) than single emulsion solvent evaporation method. Our thermal analysis studies showed no characteristic peaks for crystalline ITZ, indicating drug efficiently encapsulated inside the nanoparticle with no compatibility issues. Drug loaded PLGA-NPs preserved the antifungal activity of ITZ against Candida albicans. Drug release profile from the NPs showed an initial burst release followed by an extended release phase suggesting the potential of NPs for sustained release applications. Furthermore, ITZ encapsulated in PLGA-NPs showed enhanced intestinal permeability in the ex-vivo study. In conclusion, the developed nano-system successfully encapsulated ITZ, yielding an increased permeation and consequential antifungal activity.

Synthesis and Encapsulation of a New Zinc Phthalocyanine Photosensitizer into Polymeric Nanoparticles to Enhance Cell Uptake and Phototoxicity

Efforts to enhance the utility of photodynamic therapy as a non-invasive method for treating certain cancers have often involved the design of dye sensitizers with increased singlet oxygen efficiency. More recently, however, sensitizers with greater selectivity for tumor cells than surrounding tissue have been targeted. The present study provides an approach to the modification of the known photosensitizer zinc phthalocyanine (ZnPc), to enhance its solubility and delivery to cancer cells. Targeting a photosensitizer to the site of action improves the efficacy of the sensitizer in photodynamic therapy. In this work we used PLGA-b-PEG to encapsulate a new zinc phthalocyanine derivative, 2(3), 9(10), 16(17), 23(24)-tetrakis-(4’-methyl-benzyloxy) phthalocyanine zinc(II) (ZnPcBCH3), to enhance uptake into A549 cells, a human lung cancer cell line. ZnPcBCH3 exhibited the same photochemical properties as the parent compound ZnPc but gave increased solubility in organic solvents, which allowed for efficient encapsulation. In addition, the encapsulated dye showed a near 500-fold increase in phototoxicity for A549 cancer cells compared to free dye.

Boosting the antimicrobial action of vancomycin formulated in shellac nanoparticles of dual-surface functionality

We demonstrate a strong enhancement of the antimicrobial action of vancomycin encapsulated in shellac nanocarriers with cationic surface functionality which concentrate on the microbial cell membranes.

Nanostructured Layer-by-Layer Polyelectrolyte Containers to Switch Biofilm Fluorescence

The development of stimuli-responsive nanocontainers is an issue of utmost importance for many applications such as targeted drug delivery, regulation of the cell and tissue behavior, making bacteria have useful functions and here converting light. The present work shows a new contribution to the design of polyelectrolyte (PE) containers based on surface modified mesoporous titania particles with deposited Ag nanoparticles to achieve chemical light upconversion via biofilms. The PE shell allows slowing down the kinetics of a release of loaded l-arabinose and switching the bacteria luminescence in a certain time. The hybrid TiO₂/Ag/PE containers activated at 980 nm (IR) illumination demonstrate 10 times faster release of l-arabinose as opposed to non-activated containers. Fast IR-released l-arabinose switch bacteria fluorescence which we monitor at 510 nm. The approach described herein can be used in many applications where the target and delayed switching and light upconversion are required.

Optoacoustic imaging identifies ovarian cancer using a microenvironment targeted theranostic wormhole mesoporous silica nanoparticle

At the intersection of the newly emerging fields of optoacoustic imaging and theranostic nanomedicine, promising clinical progress can be made in dismal prognosis of ovarian cancer. An acidic pH targeted wormhole mesoporous silica nanoparticle (V7-RUBY) was developed to serve as a novel tumor specific theranostic nanoparticle detectable using multispectral optoacoustic tomographic (MSOT) imaging. We report the synthesis of a small, < 40 nm, biocompatible asymmetric wormhole pore mesoporous silica core particle that has both large loading capacity and favorable release kinetics combined with tumor-specific targeting and gatekeeping. V7-RUBY exploits the acidic tumor microenvironment for tumor-specific targeting and tumor-specific release. In vitro, treatment with V7-RUBY containing either paclitaxel or carboplatin resulted in increased cell death at pH 6.6 in comparison to drug alone (p < 0.0001). In orthotopic ovarian xenograft mouse models, V7-RUBY containing IR780 was specifically detected within the tumor 7X and 4X higher than the liver and >10X higher than in the kidney using both multispectral optoacoustic tomography (MSOT) imaging with secondary confirmation using near infrared fluorescence imaging (p < 0.0004). The V7-RUBY system carrying a cargo of either contrast agent or an anti-neoplastic drug has the potential to become a theranostic nanoparticle which can improve both diagnosis and treatment of ovarian cancer.

Starch films loaded with donut-shaped starch-quercetin microparticles: Characterization and release kinetics

Starch films loaded with donut-shaped starch-quercetin microparticles were prepared from two different botanical origins. The quercetin release kinetics through the films were studied. The donut-shaped starch-quercetin microparticles were prepared by thermal aqueous-alcoholic treatment. The quercetin loading percentage and therefore the antioxidant activity were higher for the microparticles from legume than those of cereal origins. The starch-quercetin microparticles also showed higher thermal stability than the starch granules. The starch films were produced using the solution casting method. The films with more microparticles content showed higher thermal stability. In-vitro release studies of the quercetin through the films were performed in aqueous-ethanolic medium. The quercetin released reached the equilibrium in 1 to 4 days for the films of cereal starch and in more than a week for the films of legume origin. The release data were fitted to Peppas-Sahlin model that suggests the release kinetics were controlled mainly by fickian diffusion. The produced biofilms can be utilized mainly for active food packaging applications.

Preparation of New Risperidone Depot Microspheres Based on Novel Biocompatible Poly(Alkylene Adipate) Polyesters as Long-Acting Injectable Formulations

Risperidone (RIS)-loaded microspheres based on poly(alkylene adipate)s derived from dicarboxylic acids and different aliphatic diols were prepared by the oil in water emulsion and solvent evaporation method. Specifically, 3 polyesters, namely poly(ethylene adipate), poly(propylene adipate), and poly(butylene adipate), were prepared with the aid of a 2-stage melt-polycondensation method and characterized by gel permeation chromatography, proton nuclear magnetic resonance (¹H NMR), differential scanning calorimetry, and X-ray diffraction analysis. Results showed that the molecular weight of the polyesters increased as the diol molecular weight increased, while all polymers were of semi-crystalline nature and the melting temperature was varying from 49.1°C to 51.8°C and 65.9°C for poly(propylene adipate), poly(ethylene adipate), and poly(butylene adipate), respectively. The particle size of the RIS-loaded microspheres varied from 10 to 100 μm depending on the polyester type and the drug loading, while X-ray diffraction analysis revealed amorphous active pharmaceutical ingredient in the cases of high drug-loaded microspheres. In vitro drug release studies along with scanning electron microscopy images of microspheres after the completion of dissolution process showed that in all cases RIS release was controlled by the glass transition temperature of polyesters and physical state of active pharmaceutical ingredients via diffusion.

An LTB-entrapped protein in PLGA nanoparticles preserves against enterotoxin of enterotoxigenic Escherichia coli

Objective(s):

Enterotoxigenic Escherichia coli (ETEC) is known as the most common bacterial causes of diarrheal diseases related to morbidity and mortality. Heat-labile enterotoxin (LT) is a part of major virulence factors in ETEC pathogenesis. Antigen entrapment into nanoparticles (NPs) can protect them and enhance their immunogenicity.

Materials and Methods:

In the present study, recombinant LTB protein was expressed in E. coli BL21 (DE3) and purified by an Ni-NTA agarose column. The protein was entrapped in PLGA polymer by the double emulsion method. NPs were characterized physicochemically and the protein release from the NPs was evaluated. ELISA assay was performed for investigation of raised antibody against the recombinant protein in mice. The anti-toxicity and anti-adherence attributes of the immune sera against ETEC were also evaluated.

Results:

It showed the successful cloning of a 313 bp DNA fragment encoding LTB protein in the pET28a vector. Over-expression in BL21 (DE3) led to the formation of corresponding 15.5 kDa protein bands in the SDS-PAGE gel. Western blotting by using anti-CTX confirmed the purified LTB. Protein-entrapped NPs had a spherical shape with the size of 238 nm mean diameter and 85% entrapment efficiency. Immunological analyses showed the production of a high titer of specific IgG antibody in immunized animals. The neutralizing antibody in the sera of immunized animals was approved by GM1 binding and Ileal loop assays.

Conclusion:

The results indicate the efficacy of the entrapped LTB protein as an effective immunogen which induces the humoral responses.

Porphyrin-Gold Nanomaterial for Efficient Drug Delivery to Cancerous Cells

With an aim to overcome multidrug resistance (MDR), nontargeted delivery, and drug toxicity, we developed a new nanochemotherapeutic system with tetrasodium salt of meso-tetrakis(4-sulfonatophenyl)porphyrin (TPPS) armored on gold nanoparticles (TPPS-AuNPs). The nanocarrier is able to be selectively internalized within tumor cells than in normal cells followed by endocytosis and therefore delivers the antitumor drug doxorubicin (DOX) particularly to the nucleus of diseased cells. The embedment of TPPS on the gold nanosurface provides excellent stability and biocompatibility to the nanoparticles. Porphyrin interacts with the gold nanosurface through the coordination interaction between gold and pyrrolic nitrogen atoms of the porphyrin and forms a strong association complex. DOX-loaded nanocomposite (DOX@TPPS-AuNPs) demonstrated enhanced cellular uptake with significantly reduced drug efflux in MDR brain cancer cells, thereby increasing the retention time of the drug within tumor cells. It exhibited about 9 times greater potency for cellular apoptosis via triggered release commenced by acidic pH. DOX has been successfully loaded on the porphyrin-modified gold nanosurface noncovalently with high encapsulation efficacy (∼90%) and tightly associated under normal physiological conditions but capable of releasing ∼81% of drug in a low-pH environment. Subsequently, DOX-loaded TPPS-AuNPs exhibited higher inhibition of cellular metastasis, invasion, and angiogenesis, suggesting that TPPS-modified AuNPs could improve the therapeutic efficacy of the drug molecule. Unlike free DOX, drug-loaded TPPS-AuNPs did not show toxicity toward normal cells. Therefore, higher drug encapsulation efficacy with selective targeting potential and acidic-pH-mediated intracellular release of DOX at the nucleus make TPPS-AuNPs a "magic bullet" for implication in nanomedicine.

Preparation of starch nanoparticles loaded with quercetin using nanoprecipitation technique

Nanoparticles of starches from different botanical origin were prepared by nanoprecipitation using 0.1M hydrochloric acid as non-solvent. The morphology and the particle size were analyzed using field emission scanning electron microscopy and dynamic light scattering. The nanoparticles were spherical and their sizes vary depending on the origin and the concentration of the starch solution. Starch nanoparticles loaded with quercetin were prepared. In-vitro release studies of the quercetin from the starch nanoparticles were performed in 35% ethanol as a release medium. The starch origin affects the quercetin loading percentage, the release kinetics and the antioxidant activity of the produced nanoparticles. The starch-quercetin nanoparticles from cereal origin showed the lowest loading percentage and the lowest fraction released of quercetin in comparison with nanoparticles from tuber and legume origin. The release kinetics seem to be controlled mainly by Fickian diffusion which have been revealed fitting the release data to the Peppas-Sahlin model.