Studying the effect of physically-adsorbed coating polymers on the cytotoxic activity of optimized bisdemethoxycurcumin loaded-PLGA nanoparticles

Bio synthesis, comprehensive characterization, and multifaceted therapeutic applications of BSA-Resveratrol coated platinum nanoparticles

This study examines the manufacturing, characterization, and biological evaluation of platinum nanoparticles, which were synthesized by Enterobacter cloacae and coated with Bovine Serum Albumin (BSA) and Resveratrol (RSV). The formation of PtNPs was confirmed with the change of color from dark yellow to black, which was due to the bioreduction of platinum chloride by E. cloacae. BSA and RSV functionalization enhanced these nanoparticles' biocompatibility and therapeutic potential. TGA, SEM, XRD, and FTIR were employed for characterization, where PtNPs and drug conjugation-related functional groups were studied by FTIR. XRD confirmed the crystalline nature of PtNPs and Pt-BSA-RSV NPs, while TGA and SEM showed thermal stability and post-drug coating morphological changes. Designed composite was also found to be biocompatible in nature in hemolytic testing, indicating their potential in Biomedical applications. After confirmation of PtNPs based nanocaompsite synthesis, they were examined for anti-bacterial, anti-oxidant, anti-inflammatory, and anti-cancer properties. Pt-BSA-RSV NPs showed higher concentration-dependent DPPH scavenging activity, which measured antioxidant capability. Enzyme inhibition tests demonstrated considerable anti-inflammatory activity against COX-2 and 15-LOX enzymes. In in vitro anticancer studies, Pt-BSA-RSV NPs effectively killed human ovarian cancer cells. This phenomenon was demonstrated to be facilitated by the acidic environment of cancer, as the drug release assay confirmed the release of RSV from the NP formulation in the acidic environment. Finally, Molecular docking also demonstrated that RSV has strong potential as an anti-oxidant, antibacterial, anti-inflammatory, and anticancer agent. Overall, in silico and in vitro investigations in the current study showed good medicinal applications for designed nanocomposites, however, further in-vivo experiments must be conducted to validate our findings.

Infliximab microencapsulation: an innovative approach for intra-articular administration of biologics in the management of rheumatoid arthritis-in vitro evaluation

Microencapsulation of the therapeutical monoclonal antibody infliximab (INF) was investigated as an innovative approach to improve its stability and to achieve formulations with convenient features for intra-articular administration. Ultrasonic atomization (UA), a novel alternative to microencapsulate labile drugs, was compared with the conventional emulsion/evaporation method (Em/Ev) using biodegradable polymers, specifically Polyactive® 1000PEOT70PBT30 [poly(ethylene-oxide-terephthalate)/poly(butylene-terephthalate); PEOT-PBT] and its polymeric blends with poly-(D, L-lactide-co-glycolide) (PLGA) RG502 and RG503 (PEOT-PBT:PLGA; 65:35). Six different formulations of spherical core-shell microcapsules were successfully developed and characterized. The UA method achieved a significantly higher encapsulation efficiency (69.7-80.25%) than Em/Ev (17.3-23.0%). Mean particle size, strongly determined by the microencapsulation method and to a lesser extent by polymeric composition, ranged from 26.6 to 49.9 µm for UA and 1.5-2.1 µm for Em/Ev. All formulations demonstrated sustained INF release in vitro for up to 24 days, with release rates modulated by polymeric composition and microencapsulation technique. Both methods preserved INF biological activity, with microencapsulated INF showing higher efficacy than commercial formulations at comparable doses regarding bioactive tumor necrosis factor-alpha (TNF-α) neutralization according to WEHI-13VAR bioassay. Microparticles' biocompatibility and extensive internalization by THP-1-derived macrophages was demonstrated. Furthermore, high in vitro anti-inflammatory activity was achieved after treatment of THP-1 cells with INF-loaded microcapsules, significatively reducing in vitro production of TNF-α and interleucine-6 (Il-6).

Nanocarriers significantly augment the absorption of ocular-delivered drugs: A comparative meta-analysis study

This study presents a meta-analysis that compiles information collected from several studies aiming to prove, by evidence, that nanocarriers out-perform conventional formulations in augmenting the bioavailability of ocular topically administered drugs. Data was further categorized into two subgroups; polymeric-based nanocarriers versus their lipid-based counterparts, as well as, naturally-driven carriers versus synthetically-fabricated ones. After normalization, the pharmacokinetic factor, area under the curve (AUC), was denoted as the "effect" in the conducted study, and the corresponding Forest plots were obtained. Our meta-analysis study confirmed the absorption enhancement effect of loading drugs into nanocarriers as compared to conventional topical ocular dosage forms. Interestingly, no significant differences were recorded between the polymeric and lipidic nanocarriers included in the study, while naturally-driven nanoplatforms were proven superior to the synthetic alternatives.

PEG 400:Trehalose Coating Enhances Curcumin-Loaded PLGA Nanoparticle Internalization in Neuronal Cells

This work proposes a combination of polyethylene glycol 400 (PEG) and trehalose as a surface modification approach to enhance PLGA-based nanoparticles as a drug carrier for neurons. PEG improves nanoparticles' hydrophilicity, and trehalose enhances the nanoparticle's cellular internalization by inducing a more auspicious microenvironment based on inhibiting cell surface receptor denaturation. To optimize the nanoprecipitation process, a central composite design was performed; nanoparticles were adsorbed with PEG and trehalose. PLGA nanoparticles with diameters smaller than 200 nm were produced, and the coating process did not considerably increase their size. Nanoparticles entrapped curcumin, and their release profile was determined. The nanoparticles presented a curcumin entrapment efficiency of over 40%, and coated nanoparticles reached 60% of curcumin release in two weeks. MTT tests and curcumin fluorescence, with confocal imaging, were used to assess nanoparticle cytotoxicity and cell internalization in SH-SY5Y cells. Free curcumin 80 µM depleted the cell survival to 13% at 72 h. Contrariwise, PEG:Trehalose-coated curcumin-loaded and non-loaded nanoparticles preserved cell survival at 76% and 79% under the same conditions, respectively. Cells incubated with 100 µM curcumin or curcumin nanoparticles for 1 h exhibited 13.4% and 14.84% of curcumin's fluorescence, respectively. Moreover, cells exposed to 100 µM curcumin in PEG:Trehalose-coated nanoparticles for 1 h presented 28% fluorescence. In conclusion, PEG:Trehalose-adsorbed nanoparticles smaller than 200 nm exhibited suitable neural cytotoxicity and increased cell internalization proficiency.

Liposomal Drug Delivery And Its Potential Impact On Cancer Research

Liposomes are one of the most versatile drug carriers due to their functional properties, such as higher biocompatibility, the ability to encapsulate hydrophilic and hydrophobic products, and higher biodegradability. Liposomes are a better and more significant nanocarrier for cancer therapy. The key to developing a better cancer-targeted nanocarrier is the development of targeted liposomes using various approaches. Several traditional and novel liposome preparation methods are briefly discussed in this mini-review. The current state of liposome targeting, active and passive liposome targeting in cancer therapy, ligand directed targeting (antibody, aptamer, and protein/peptide-mediated targeting), and other miscellaneous approaches such as stimuli-responsive liposome-based targeting, autophagy inhibition mediated targeting, and curcumin loaded liposomal targeting are all discussed within. All of this gathered and compiled information will shed new light on liposome targeting strategies in cancer treatment and will pique the interest of aspiring researchers and academicians.

Dual-reactive nanogels for orthogonal functionalization of hydrophilic shell and amphiphilic network

Amphiphilic nanogels (NGs) combine a soft, water-swollen hydrogel matrix with internal hydrophobic domains. While these domains can encapsulate hydrophobic cargoes, the amphiphilic particle surface can reduce colloidal stability and/or limit biological half-life. Therefore, a functional hydrophilic shell is needed to shield the amphiphilic network and tune interactions with biological systems. To adjust core and shell properties independently, we developed a synthetic strategy that uses preformed dual-reactive nanogels. In a first step, emulsion copolymerization of pentafluorophenyl methacrylate (PFPMA) and a reduction-cleavable crosslinker produced precursor particles for subsequent network modification. Orthogonal shell reactivity was installed by using an amphiphilic block copolymer (BCP) surfactant during this particle preparation step. Here, the hydrophilic block poly(polyethylene glycol methyl ether methacrylate) (PPEGMA) contains a reactive alkyne end group for successive functionalization. The hydrophobic block (P(PFPMA-co-MAPMA) contains random methacryl-amido propyl methacrylamide (MAPMA) units to covalently attach the surfactant to the growing PPFPMA network. In the second step, orthogonal modification of the core and shell was demonstrated. Network functionalization with combinations of hydrophilic (acidic, neutral, or basic) and hydrophobic (cholesterol) groups gave a library of pH- and redox-sensitive amphiphilic NGs. Stimuli-responsive properties were demonstrated by pH-dependent swelling and reduction-induced degradation via dynamic light scattering. Subsequently, copper-catalyzed azide-alkyne cycloaddition was used to attach azide-modified rhodamine as model compound to the shell (followed by UV-Vis). Overall, this strategy provides a versatile platform to develop multi-functional amphiphilic nanogels as carriers for hydrophobic cargoes.

Recent Advances in the Surface Functionalization of PLGA-Based Nanomedicines

Therapeutics are habitually characterized by short plasma half-lives and little affinity for targeted cells. To overcome these challenges, nanoparticulate systems have entered into the disease arena. Poly(d,l-lactide-co-glycolide) (PLGA) is one of the most relevant biocompatible materials to construct drug nanocarriers. Understanding the physical chemistry of this copolymer and current knowledge of its biological fate will help in engineering efficient PLGA-based nanomedicines. Surface modification of the nanoparticle structure has been proposed as a required functionalization to optimize the performance in biological systems and to localize the PLGA colloid into the site of action. In this review, a background is provided on the properties and biodegradation of the copolymer. Methods to formulate PLGA nanoparticles, as well as their in vitro performance and in vivo fate, are briefly discussed. In addition, a special focus is placed on the analysis of current research in the use of surface modification strategies to engineer PLGA nanoparticles, i.e., PEGylation and the use of PEG alternatives, surfactants and lipids to improve in vitro and in vivo stability and to create hydrophilic shells or stealth protection for the nanoparticle. Finally, an update on the use of ligands to decorate the surface of PLGA nanomedicines is included in the review.

Synchronizing In Silico, In Vitro, and In Vivo Studies for the Successful Nose to Brain Delivery of an Anticancer Molecule

Sesamol is a sesame seed constituent with reported activity against many types of cancer. In this work, two types of nanocarriers, solid lipid nanoparticles (SLNs) and polymeric nanoparticles (PNs), were exploited to improve sesamol efficiency against the glioma cancer cell line. The ability of the proposed systems for efficient brain targeting intranasally was also inspected. By the aid of two docking programs, the virtual loading pattern inside these nanocarriers was matched to the real experimental results. Interactions involved in sesamol-carrier binding were also assessed, followed by a discussion of how different scoring functions account for these interactions. The study is an extension of the computer-assisted drug formulation design series, which represents a promising initiative for an upcoming industrial innovation. The results proved the power of combined in silico tools in predicting members with the highest sesamol payload suitable for delivering a sufficient dose to the brain. Among nine carriers, glyceryl monostearate (GMS) and polycaprolactone (PCL) scored the highest sesamol payload practically and computationally. The EE % was 66.09 ± 0.92 and 61.73 ± 0.47 corresponding to a ΔG (binding energy) of -8.85 ± 0.16 and -5.04 ± 0.11, respectively. Dynamic light scattering evidenced the formation of 215.1 ± 7.2 nm and 414.25 ± 1.6 nm nanoparticles, respectively. Both formulations demonstrated an efficient cytotoxic effect and brain-targeting ability compared to the sesamol solution. This was evidenced by low IC₅₀ (38.50 ± 10.37 μM and 27.81 ± 2.76 μM) and high drug targeting efficiency (7.64 ± 1.89-fold and 13.72 ± 4.1-fold) and direct transport percentages (86.12 ± 3.89 and 92.198 ± 2.09) for GMS-SLNs and PCL-PNs, respectively. The results also showed how different formulations, having different compositions and characteristics, could affect the cytotoxic and targeting ability.

Evaluation of Antiproliferative Palladium(II) Complexes of Synthetic Bisdemethoxycurcumin towards In Vitro Cytotoxicity and Molecular Docking on DNA Sequence

Metallodrugs form a large family of therapeutic agents against cancer, among which is cisplatin, a paradigmatic member. Therapeutic resistance and undesired side effects to Pt(II) related drugs, prompts research on different metal-ligand combinations with potentially enhanced biological activity. We present the synthesis and biological tests of novel palladium(II) complexes containing bisdemethoxycurcumin (BDMC) 1 and 2. Complexes were fully characterized and their structures were determined by X-ray diffraction. Their biological activity was assessed for several selected human tumor cell lines: Jurkat (human leukaemic T-cell lymphoma), HCT-116 (human colorectal carcinoma), HeLa (human cervix epitheloid carcinoma), MCF-7 (human breast adenocarcinoma), MDA-MB-231 (human mammary gland adenocarcinoma), A549 (human alveolar adenocarcinoma), Caco-2 (human colorectal carcinoma), and for non-cancerous 3T3 cells (murine fibroblasts). The cytotoxicity of 1 is comparable to that of cisplatin, and superior to that of 2 in all cell lines. It is a correlation between IC50 values of 1 and 2 in the eight studied cell types, promising a potential use as anti-proliferative drugs. Moreover, for Jurkat cell line, complexes 1 and 2, show an enhanced activity. DFT and docking calculations on the NF-κB protein, Human Serum Albumin (HSA), and DNA were performed for 1 and 2 to correlate with their biological activities.

Design, synthesis, and antitumor activity of PLGA nanoparticles incorporating a discovered benzimidazole derivative as EZH2 inhibitor

PURPOSE

Targeting enhancer of zeste homolog 2 (EZH2) can represent a hopeful strategy for oncotherapy. Also, the use of PLGA-based nanoparticles as a novel and rate-controlling carrier system was of our concern.

METHODS

Benzimidazole derivatives were synthesized, and their structures were clarified. In vitro antitumor activity was evaluated. Then, a modeling study was performed to investigate the ability of the most active compounds to recognize EZH2 active sites. Compound 30 (Drug) was selected to conduct pre-formulation studies and then it was incorporated into polymeric PLGA nanoparticles (NPs). NPs were then fully characterized to select an optimized formula (NP₄) that subjected to further evaluation regarding antitumor activity and protein expression levels of EZH2 and EpCAM.

RESULTS

The results showed the antitumor activity of some synthesized derivatives. Docking outcomes demonstrated that Compound 30 was able to identify EZH2 active sites. NP₄ exhibited promising findings and proved to keep the antitumor activity of Compound 30. HEPG-2 was the most sensitive for both Drug and NP₄. Protein analysis indicated that Drug and NP₄ had targeted EZH2 and the downstream signaling pathway leading to the decline of EpCAM expression.

CONCLUSIONS

Targeting EZH2 by Compound 30 has potential use in the treatment of cancer especially hepatocellular carcinoma.

Augmented cytotoxicity using the physical adsorption of Poloxamer 188 on allicin-loaded gelatin nanoparticles

OBJECTIVES

The aim of this work was to study the effect of the physically adsorbed Poloxamer 188 coating polymer on the cytotoxic activity of allicin-loaded gelatin nanoparticles.

METHODS

The double desolvation method was utilised to prepare the nanoparticles which were characterised for particle size (PS), polydispersity index (PDI) and zeta potential and visualised using transmission electron microscopy. The coating density of the used polymer was determined using 1H-nuclear magnetic resonance (1H-NMR); 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to evaluate the cytotoxicity on HepG-2 cell lines.

KEY FINDINGS

The particles were spherical possessing a PS of 714 ± 25.21 nm and a PDI of 0.663 ± 0.143. These results together with the 1H-NMR results analysis confirmed the efficient coating of Poloxamer 188. The coating of particles rendered them more cytotoxic, scoring an IC50 of 6.736 µm (2-folds lower than the uncoated counter parts and 4-folds lesser than the allicin solution), and apt for cancer-targeting. Moreover, the prepared nanoparticles were stable to gamma-sterilisation and to a storage of 12 months.

CONCLUSIONS

Augmented cytotoxicity on HepG-2 cell lines was obtained using the physical adsorption of an abundant and relatively cheap material, Poloxamer 188, on allicin-loaded gelatin nanoparticles.

Enhancement of oral bioavailability of drugs using lipid-based carriers: a meta-analysis study

Cancer is the disease of this era. Its therapy is moving through ups and downs not only due to poor effectiveness of many treating drugs, but also due to the serious side effects always evolving. In an attempt to overcome this problem, many systems, including lipid-based carriers, have been exploited for their oral delivery. Throughout this study, the meta-analysis tool was used to combine data from different studies and extract evidences that lipid-based carriers enhance the oral bioavailability. Consequently, increasing the efficiency and the reduction in side effects of drugs would follow. Accordingly, the usual parameter to indicate the bioavailability; the area under effect curve (AUC) was used where the lipid carriers have proven their superiority over conventional formulations. Interestingly, by comparing microemulsion/self-microemulsifying system (SMEDDS) versus liposomes/pro-liposomes as subgroups of the meta-analysis study, insignificant differences were recorded between them.

RETRACTED: Pluronic® F127 stabilized reduced graphene oxide hydrogel for the treatment of psoriasis: In vitro and in vivo studies

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editors. Significant similarities were noticed post-publication between this article and an article submitted to the journal on the same day, by an apparently unrelated research group: Hui Li, Yanlu Jia and Chunling Liu, Colloids and Surfaces B: Biointerfaces 195 (2020) 111259 https://doi.org/10.1016/j.colsurfb.2020.111259. Moreover, the authors did not respond to the journal request to comment on these similarities and to provide the raw data, and the Editors decided to retract the article. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and genuine. As such this article represents a severe abuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process. Although this article was published earlier than the article from Colloids and Surfaces B: Biointerfaces 195 (2020) 111259, the Editors decided to retract this article given the concerns on the reliability of the data.

RETRACTED: Sustained delivery of epalrestat to the retina using PEGylated solid lipid nanoparticles laden contact lens

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). This article has been retracted at the request of the Editor-in-Chief. Significant similarities were noticed post-publication between this article and an article submitted to the Journal of Drug Delivery Science and Technology on the same day, by an apparently unrelated research group: Tong Zhang, Tianhui Zhu, Fanyin Wang, Ling Peng and Mingying Lai 60 (2020) 101949 https://doi.org/10.1016/j.jddst.2020.101949 Moreover, the authors did not respond to the journal request to comment on these similarities and to provide the raw data, and the Editor-in-Chief decided to retract the article. One of the conditions of submission of a paper for publication is that authors declare explicitly that their work is original and genuine. As such this article represents a severe abuse of the scientific publishing system.

Ultrabright Fluorescent Polymeric Nanoparticles with a Stealth Pluronic Shell for Live Tracking in the Mouse Brain

Visualizing single organic nanoparticles (NPs) in vivo remains a challenge, which could greatly improve our understanding of the bottlenecks in the field of nanomedicine. To achieve high single-particle fluorescence brightness, we loaded polymer poly(methyl methacrylate)-sulfonate (PMMA-SO₃H) NPs with octadecyl rhodamine B together with a bulky hydrophobic counterion (perfluorinated tetraphenylborate) as a fluorophore insulator to prevent aggregation-caused quenching. To create NPs with stealth properties, we used the amphiphilic block copolymers pluronic F-127 and F-68. Fluorescence correlation spectroscopy and Förster resonance energy transfer (FRET) revealed that pluronics remained at the NP surface after dialysis (at one amphiphile per 5.5 nm²) and prevented NPs from nonspecific interactions with serum proteins and surfactants. In primary cultured neurons, pluronics stabilized the NPs, preventing their prompt aggregation and binding to neurons. By increasing dye loading to 20 wt % and optimizing particle size, we obtained 74 nm NPs showing 150-fold higher single-particle brightness with two-photon excitation than commercial Nile Red-loaded FluoSpheres of 39 nm hydrodynamic diameter. The obtained ultrabright pluronic-coated NPs enabled direct single-particle tracking in vessels of mice brains by two-photon intravital microscopy for at least 1 h, whereas noncoated NPs were rapidly eliminated from the circulation. Following brain injury or neuroinflammation, which can open the blood-brain barrier, extravasation of NPs was successfully monitored. Moreover, we demonstrated tracking of individual NPs from meningeal vessels until their uptake by meningeal macrophages. Thus, single NPs can be tracked in animals in real time in vivo in different brain compartments and their dynamics visualized with subcellular resolution.

Filgrastim loading in PLGA and SLN nanoparticulate system: a bioinformatics approach

OBJECTIVE

In this research work, we hypothesized to predict the nanoparticulate system, best suited for targeted delivery of filgrastim. Significance: Targeted delivery of filgrastim to bone marrow is required to decrease the incidence of neutropenia/febrile neutropenia. This is achieved by nanoparticulate systems, duly designed by bioinformatics approach.

METHOD

The targeted delivery of filgrastim in nanoparticulate system was achieved by molecular dynamics (MD) simulation studies. Two matrices comprising PLGA and SLN (tripalmitin, core component of SLN system) were modeled separately with proposed drug filgrastim. Energy minimization of all systems was done using the steepest descent method. PLGA and tripalmitin systems were equalized at 310 °C, at 1 bar pressure with Berendsen barostat for 200 ps using a v-rescale thermostat for 100 ps. Atomistic MD simulations of four model system and mass density of interacting systems were calculated.

RESULTS

The mass density maps of each nanoparticle system, that is, PLGA and tripalmitin showed an increase in density toward the end of the simulation. The contact numbers attained equilibria with the average number of approx.. 1500 contacts in case of tripalmitin-filgrastim system. While PLGA-filgrastim system shows lesser contacts as compared to tripalmitin with average contacts of approx. 1000.The binding free energy was predicted to be -1104 kJ/mol in tripalmitin-filgrastim complex and -421 kJ/mol in PLGA-filgrastim system.

CONCLUSION

Findings of study revealed that both nanoparticle systems assumed to be good model for drug-carrier systems. Though SLN systems were thought to be more appropriate than PLGA, still the in vivo findings could ascertain this hypothesis in futuristic work.

Design of expert guided investigation of native L-asparaginase encapsulated long-acting cross-linker-free poly (lactic-co-glycolic) acid nanoformulation in an Ehrlich ascites tumor model

Present study explores native L-asparaginase encapsulated long-acting cross-linker-free PLGA-nanoformulation in an Ehrlich ascites tumor model. L-asparaginase-PLGA nanoparticles for tumor were prepared using a double emulsion solvent evaporation technique, optimized and validated by Box-Behnken Design. L-ASN-PNs showed a particle size of 195 nm ± 0.2 nm and a PDI of 0.2. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) techniques revealed its smooth morphology and elicited an in-vitro release of 80% of the drug, following the Higuchi drug release model. In-vivo studies of L-ASN-PNs on an Ehrlich ascites tumor (EAT) model were completed and compared with the standard medication of 5-fluorouracil (5-FU) treatment. L-ASN-PN treated mice showed a 51.15% decrease in tumor volume and 100% survival rate with no reduction in body weight, no haemotoxicity and no hepatotoxicity, as evident from the hematological parameters, and liver enzyme parameters that were well within the prescribed limits. Chemotherapy has severe side effects and restricted therapeutic success. Henceforth, the purported L-Asparaginase PLGA nanoparticles are a suitable entity for better tumor regression, intra-tumor accumulation and no hematological side-effects.

Prediction of Drug Loading in the Gelatin Matrix Using Computational Methods

The delivery of drugs is a topic of intense research activity in both academia and industry with potential for positive economic, health, and societal impacts. The selection of the appropriate formulation (carrier and drug) with optimal delivery is a challenge investigated by researchers in academia and industry, in which millions of dollars are invested annually. Experiments involving different carriers and determination of their capacity for drug loading are very time-consuming and therefore expensive; consequently, approaches that employ computational/theoretical chemistry to speed have the potential to make hugely beneficial economic, environmental, and health impacts through savings in costs associated with chemicals (and their safe disposal) and time. Here, we report the use of computational tools (data mining of the available literature, principal component analysis, hierarchical clustering analysis, partial least squares regression, autocovariance calculations, molecular dynamics simulations, and molecular docking) to successfully predict drug loading into model drug delivery systems (gelatin nanospheres). We believe that this methodology has the potential to lead to significant change in drug formulation studies across the world.

Particulate Systems in the Enhancement of the Antiglaucomatous Drug Pharmacodynamics: A Meta-Analysis Study

Glaucoma is a very serious disease that can lead to blindness in severe cases. In an attempt to increase the efficacy of the drugs used in treating this disease, many particulate systems (micro/nano and lipid-based/nonlipid-based) have been exploited. In this study, the meta-analysis approach was implemented in order to explore the published studies and extract the literature-based evidence (proof-of-concept studies = 16) that the particulate systems increase the efficiency of the investigated intraocular pressure drugs as demonstrated by the increase in the area under effect curve. Comparison of micron particles versus nanoparticles on the one hand and lipid-based versus nonlipid-based on the other hand, as subgroups of the meta-analysis, was also included in the study where the latter comparison led to insignificant differences, whereas the former has proven the superiority of the nanoparticles over the micronized counterparts.

Black Phosphorus-Based Multimodal Nanoagent: Showing Targeted Combinatory Therapeutics against Cancer Metastasis

In breast cancer chemophotothermal therapy, it is a great challenge for the development of multifunctional nanoagents for precision targeting and the effective treatment of tumors, especially for metastasis. Herein, we successfully design and synthesize a multifunctional black phosphorus (BP)-based nanoagent, BP/DTX@PLGA, to address this challenge. In this composite nanoagent, BP quantum dots (BPQDs) are loaded into poly(lactic-co-glycolic acid) (PLGA) with additional conjugation of a chemotherapeutic agent, docetaxel (DTX). The in vivo distribution results demonstrate that BP/DTX@PLGA shows striking tropism for targeting both primary tumors and lung metastatic tumors. Moreover, BP/DTX@PLGA exhibits outstanding controllable chemophotothermal combinatory therapeutics, which dramatically improves the efficacy of photothermal tumor ablation when combined with near-light irradiation. Mechanistically, accelerated DTX release from the nanocomplex upon heating and thermal treatment per se synergistically incurs apoptosis-dependent cell death, resulting in the elimination of lung metastasis. Meanwhile, in vitro and in vivo results further confirm that BP/DTX@PLGA possesses good biocompatibility. This study provides a promising BP-based multimodal nanoagent to constrain cancer metastasis.

Effect of surfactant on the size and stability of PLGA nanoparticles encapsulating a protein kinase C inhibitor

Nowadays many drugs with improved therapeutic efficacy are discovered but cannot be utilized due to their low solubility and insufficient bioavailability. An example of such a drug molecule is a protein kinase C inhibitor that influences an enzyme which plays an important role in several signal transduction cascades. The aim of this study was to formulate a stable nanoparticle dispersion of the PKC inhibitor encapsulated into PLGA nanoparticles (NPs). Encapsulation of the PKC inhibitor into PLGA NPs of 100-200 nm diameter should provide a targeted delivery to the inflammation sites. The NPs were prepared via nanoprecipitation and different surfactants were investigated: Fully and partially hydrolyzed poly(vinyl alcohol) (PVA, Mowiol X-88 and X-98), poloxamers (Pluronic F68 and F127) and polysorbates (Tween 20 and 80). From all surfactants tested, only NPs prepared with partially hydrolyzed PVA (Mowiol X-88) provided the desired stability throughout the downstream processes. These NPs were subsequently analyzed regarding their particle size, polydispersity, encapsulation efficiency and loading capacity. Dynamic light scattering results revealed that monodisperse NPs of 150-220 nm were formed, a size range that favors targeted delivery. The drug encapsulation efficiency varied from 31 to 75% with a drug loading of 1.3-2%. Moreover, the long-term stability was studied and the residual amount of PVA of the NP solutions was quantified via nuclear magnetic resonance (NMR) measurements. The shell-less hen's egg model was used to test toxic effects (hemorrhage, vascular lysis, thrombosis, hemolysis and lethality) of the NPs in a more complex biological system under dynamic flow conditions.

Formulation of Antimicrobial Tobramycin Loaded PLGA Nanoparticles via Complexation with AOT

Tobramycin is a potent antimicrobial aminoglycoside and its effective delivery by encapsulation within nanoparticle carriers could increase its activity against infections through a combination of sustained release and enhanced uptake. Effective antimicrobial therapy against a clinically relevant model bacteria (Pseudomonas aeruginosa) requires sufficient levels of therapeutic drug to maintain a drug concentration above the microbial inhibitory concentration (MIC) of the bacteria. Previous studies have shown that loading of aminoglycoside drugs in poly(lactic-co-glycolic) acid (PLGA)-based delivery systems is generally poor due to weak interactions between the drug and the polymer. The formation of complexes of tobramycin with dioctylsulfosuccinate (AOT) allows the effective loading of the drug in PLGA-nanoparticles and such nanoparticles can effectively deliver the antimicrobial aminoglycoside with retention of tobramycin antibacterial function.

The differential cellular uptake of curcuminoids in vitro depends dominantly on albumin interaction

BACKGROUND

Curcuminoids, mainly present in the plant rhizomes of turmeric (Curcuma longa), consist of mainly three forms (curcumin (CUR), bisdemethoxycurcumin (BDMC) and demethoxycurcumin (DMC)). It has been reported that different forms of curcuminoids possess different biological activities. However, the mechanisms associated with these differences are not well-understood. Recently, our laboratory found differences in the cellular uptake of these curcuminoids. Therefore, it has been inferred that these differences contribute to the different biological activities.

PURPOSE

In this study, we investigated the mechanisms of differential cellular uptake of these curcuminoids.

METHOD

Based on our previous study, we hypothesized the differential cellular uptake is caused by (I) polarity, (II) transporters, (III) metabolism rate of curcuminoids and (IV) medium components. These four hypotheses were each investigated by (I) neutralizing the polarities of curcuminoids by encapsulation into poly(lactic-co-glycolic) acid nanoparticles (PLGA-NPs), (II) inhibition of polyphenol-related absorption transporters, (III) analysis of the cellular curcuminoids and their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and (IV) use of different mediums in cell study.

RESULTS

The differential cellular uptake was not affected by (I-III). However, when investigating (IV), not only CUR but also BDMC and DMC were incorporated into cells when serum free media was used. Furthermore, when we used the serum free medium containing bovine serum albumin (BSA), only CUR was taken up but BDMC and DMC were not. Therefore, we identified that the differential cellular uptake of curcuminoids is caused by the medium components, especially BSA. Also, the fluorescence quenching study suggested that differential cellular uptake is due to the different interaction between BSA and each curcuminoid.

CONCLUSION

The differential cellular uptake of curcuminoids was caused by the different interaction between curcuminoids and BSA. The results from this study might give clues on the mechanisms by which curcuminoids exhibit different physiological activities.

Enhanced immunosuppressive effects of 3,5-bis[4(diethoxymethyl)benzylidene]-1-methyl-piperidin-4-one, an α, β-unsaturated carbonyl-based compound as PLGA-b-PEG nanoparticles

Background: 3,5-Bis[4-(diethoxymethyl)benzylidene]-1-methyl-piperidin-4-one (BBP), a novel synthetic curcumin analogue has been revealed to possess strong in vitro and in vivo immunosuppressive effects. Purpose: The aim of present study was to prepare and characterize BBP-encapsulated polylactic-co-glycolic acid-block-polyethylene glycol (PLGA-b-PEG) nanoparticles and to evaluate its in vivo efficacy against innate and adaptive immune responses. Methods: Male BALB/c mice were orally administered with BBP alone and BBP- encapsulated nanoparticles equivalent to 5, 10 and 20 mg/kg of BBP in distilled water for a period of 14 days. The immunomodulatory potential was appraised by determining its effects on non-specific and specific immune parameters. Results: The results showed that BBP was successfully encapsulated in PLGA-b-PEG polymer with 154.3 nm size and high encapsulation efficiency (79%) while providing a sustained release for 48 hours. BBP nanoparticles showed significant enhanced dose-dependent reduction on the migration of neutrophils, Mac-1 expression, phagocytic activity, reactive oxygen species (ROS) production, serum levels of ceruloplasmin and lysozyme, immunoglobulins and myloperoxidase (MPO) plasma levels when compared to unencapsulated BBP. Enhanced dose-dependent inhibition was also observed on lymphocyte proliferation along with the downregulation of effector cells expression and release of cytokines, and reduction in rat paw oedema in BBP nanoparticles treated mice. At higher doses the suppressive effects of the BBP nanoparticles on various cellular and humoral parameters of immune responses were comparable to that of cyclosporine-A at 20 mg/kg. Conclusion: These findings suggest that the immunosuppressive effects of BBP were enhanced as PLGA-b-PEG nanoparticles.

Gelatin Nanoparticles

Currently, gelatin nanoparticles are gaining more grounds in drug and gene delivery throughout all the available several routes of administration. Yet, the homogenous and less disperse preparation of this type of nanoparticles is still a challenging task due to the variation of the gelatin quality according to its source and due to its variable molecular weight. Accordingly, several methods were proposed from which the double-desolvation method has been proven to yield optimum results regarding particle size and homogeneity. Thereby, we describe in this chapter a detailed procedure of this method. We also introduce our protocols of the cationization of this kind of nanoparticles as it is extensively needed in case of loading genetic materials or proteins. Additionally, FITC labeling of gelatin nanoparticles that is usually utilized for purposes of imaging or bio-distribution studies is also introduced step by step.

Bioinspired Shielding Strategies for Nanoparticle Drug Delivery Applications

Nanoparticle delivery systems offer advantages over free drugs, in that they increase solubility and biocompatibility. Nanoparticles can deliver a high payload of therapeutic molecules while limiting off-target side effects. Therefore, delivery of an existing drug with a nanoparticle frequently results in an increased therapeutic index. Whether of synthetic or biologic origin, nanoparticle surface coatings are often required to reduce immune clearance and thereby increase circulation times allowing the carriers to reach their target site. To this end, polyethylene glycol (PEG) has long been used, with several PEGylated products reaching clinical use. Unfortunately, the growing use of PEG in consumer products has led to an increasing prevalence of PEG-specific antibodies in the human population, which in turn has fueled the search for alternative coating strategies. This review highlights alternative bioinspired nanoparticle shielding strategies, which may be more beneficial moving forward than PEG and other synthetic polymer coatings.

Controlled Dye Aggregation in Sodium Dodecylsulfate-Stabilized Poly(methylmethacrylate) Nanoparticles as Fluorescent Imaging Probes

Polymer nanoparticles are used extensively in biomedical applications. Poly(methylmethacrylate) (PMMA) nanoparticles obtained via nanoprecipitation were unstable and flocculate or precipitate from solution within a few hours. A simple method to improve the stability of the particles using surfactants at low concentrations was carried out to produce PMMA nanoparticles with long-term stability in water (>6 months). The increased stability was attributed to the incorporation of surfactants inside the polymer particles during nanoprecipitation. The same methodology was also adopted to encapsulate a highly fluorescent hydrophobic perylene tetraester inside the polymer nanoparticles with good stability in water. Because of the presence of the anionic sodium dodecyl sulfate, the particles showed a negative zeta potential of -34.7 mV and an average size of 150 nm. Similarly, the dye-encapsulated polymer nanoparticles showed a zeta potential of -35.1 mV and an average particle size of 180 nm. By varying the concentration of encapsulated dyes inside the polymer nanoparticles, dye aggregation could be controlled, and the fluorescence profiles of the nanoparticles were altered. To understand the uptake and toxicity of the polymer nanoparticles, baby hamster kidney cells were chosen as a model system. The polymer nanoparticles were taken up by the cells within 3 h and were nontoxic at concentrations as high as 100 ppm. The confocal micrographs of the cells revealed localized fluorescence from the polymer nanoparticles around the nucleus in the cytoplasm without the penetration of the nuclear envelope.

Exploring gelatin nanoparticles as novel nanocarriers for Timolol Maleate: Augmented in-vivo efficacy and safe histological profile

The use of gelatin has been gaining recognition in ocular delivery for its safety profile and biocompatible properties. Timolol Maleate (TM) is an anti-glaucoma drug possessing poor corneal penetration while causing eye irritation making it an ideal candidate for novel nanoparticulate systems. Timolol Maleate loaded Gelatin Nanoparticles (GNPs) were prepared using the double desolvation method utilizing glutaraldehyde as the crosslinking agent. Optimization of the nanoparticles was achieved through a full-factorial design. An optimum formulation possessing particle size of 205 nm, zetapotential of 12.5 mV and an entrapment efficiency of 74.72% was selected. TEM imaging of the optimized nanoparticles was performed and the stability was tracked over 6 months. The in-vitro release studies showed a burst effect followed by a sustained profile. The selected formulae were tested in-vivo and compared to a Timolol marketed product on albino rabbits and were proven superior regarding intraocular pressure lowering and sustained efficacy. The prepared nanoparticles successfully passed Draize irritancy test and showed normal histology. These data indicate that the prepared GNPs possessed all needed qualities of a successful ocular system; corneal affinity, suitable particle size, high entrapment efficiency, sustained release, good stability, efficient lowering of intraocular pressure, high drug bioavailability and lack of irritancy.

Preparation of poly(lactide-co-glycolide) microspheres and evaluation of pharmacokinetics and tissue distribution of BDMC-PLGA-MS in rats

The aim of the present study was to develop a novel long-acting Poly (lactic-co-glycolic acid) (PLGA)-based microspheres formulation of Bisdemethoxycurcum (BDMC) by emulsion-solvent evaporation method. Meanwhile, the effects of the volume ratio of the dispersed phase and continuous phase, the concentration of PLGA and PVA, the theoretical drug loading and stirring speed were investigated. The mean diameter of the microspheres was 8.5 µm and the size distribution was narrow. The encapsulation efficiency (EE) and drug loading efficiency (DLE) of BDME loaded PLGA microspheres (BDMC-PLGA-MS) was 94.18% and 8.14%, respectively. In an in vitro study of drug release, it can be concluded that the BDMC-PLGA-MS exhibited sustained and long-term release properties for 96 h. Stability studies suggested that the microspheres we prepared had a very good stability. Furthermore, the results of an in vivo study indicated that the BDMC-PLGA-MS had sustained release effect and was mainly distributed in the lung tissue, and less distribution in other tissues, which indicated that microspheres could be an effective parenteral carrier for the delivery of BDMC in lung cancer treatment.

Anti-tumor efficacy of an integrated methyl dihydrojasmonate transdermal microemulsion system targeting breast cancer cells: In vitro and in vivo studies

Targeting solid tumors transdermally is an emerging approach that is currently under intense investigation. In this context, microemulsions are reported as one of the most favored carriers for successful transdermal drug delivery. Thereby, these nano-carriers were utilized in this study for the delivery of a phytochemical, namely methyl dihydrojasmonate (MDHJ), which has previously demonstrated an anticancer effect. Accordingly, pseudoternary phase diagrams were constructed using several combinations of oils, surfactants and co-surfactants and following the water titration method. Two systems were selected and an experimental design (Simplex Lattice Mixture Design) was utilized to select formulations for further investigation through an ex vivo permeation study through mouse skin. Transdermal fluxes were determined reaching a value of 0.07μlcm^-2h^-1. Cytotoxicity studies were carried out where the selected superlative formulation was further investigated on MCF-7 cell lines and scored an IC₅₀ of 42.2μl/ml (equivalent to 8.3μl/ml drug). Further, in vivo investigations were performed using Ehlirch solid carcinoma and histopathological examination of the tumor cells evaluating the tumor volume differences, tumor inhibition percentages and the necrotic effect of the formulation compared to control, placebo and pure drug. The obtained results showed significant anticancer effects of the selected formulation when applied on the tumor bearing mice skin.