Effects of particle size and surface modification on cellular uptake and biodistribution of polymeric nanoparticles for drug delivery

Cyclodextrin pendant polymer as an efficient drug carrier for scutellarin

A novel β-cyclodextrin pendant polymer (ε-PL-CD), composed of poly(ε-lysine) (ε-PL) main chain and glycine-β-cyclodextrin (Gly-CD) side chains, was prepared by a simple two-step procedure. The ε-PL-CD was investigated as a drug carrier of hydrophobic drug scutellarin (SCU). The characterization and complexation mode of the SCU:ε-PL-CD were researched in both solution and solid state by means of photoluminescence spectroscopy, ¹H and 2D NMR, X-Ray powder diffraction (XRPD), thermal gravimetric analysis, Particle size and Zeta potential. The solubility test indicated that the solubilizing ability of SCU:ε-PL-CD was significantly improved compared with SCU:β-CD and free SCU. Besides, in vitro cell experiment, it was found that SCU:ε-PL-CD has a strong inhibitory effect on the growth and invasion of tumor cells. The present study provides useful information for ε-PL-CD as a drug carrier material.

Antibacterial Effect of Chitosan-Gold Nanoparticles and Computational Modeling of the Interaction between Chitosan and a Lipid Bilayer Model

Pathogenic bacteria have the ability to develop antibiotic resistance mechanisms. Their action consists mainly in the production of bacterial enzymes that inactivate antibiotics or the appearance of modifications that prevent the arrival of the drug at the target point or the alteration of the target point itself, becoming a growing problem for health systems. Chitosan-gold nanoparticles (Cs-AuNPs) have been shown as effective bactericidal materials avoiding damage to human cells. In this work, Cs-AuNPs were synthesized using chitosan as the reducing agent, and a systematic analysis of the influence of the synthesis parameters on the size and zeta potential of the Cs-AuNPs and their UV-vis spectra was carried out. We used a simulation model to characterize the interaction of chitosan with bacterial membranes, using a symmetric charged bilayer and two different chitosan models with different degrees of the chitosan amine protonation as a function of pH, with the aim to elucidate the antibacterial mechanism involving the cell wall disruption. The Cs-AuNP antibacterial activity was evaluated to check the simulation model.

Efavirenz Loaded Nanostructured Lipid Carriers for Efficient and Prolonged Viral Inhibition in HIV-Infected Macrophages

Background: The clinical outcome of anti-HIV therapy is poor due to the inherent fallouts ofanti-HIV therapy. It is further worsened due to the presence of viral reservoirs in immune cellslike the macrophages. An ideal anti-HIV therapy must reach, deliver the drug and exert itsaction inside macrophages. To address this, we developed novel cationic nanostructured lipidcarriers of efavirenz (cationic EFV-NLC). Methods: The developed cationic EFV NLCs were evaluated for particle size, zeta potential,encapsulation efficiency, in-vitro drug release, DSC, XRD, TEM, cytotoxicity, cellular uptakestudies and anti-HIV efficacy in a monocyte-derived macrophage cell line (THP-1). Results: Cationic EFV-NLCs showed high encapsulation efficiency (90.54 ± 1.7%), uniformparticle size distribution (PDI 0.3-0.5 range) and high colloidal stability with positive zetapotential (+23.86 ± 0.49 mV). DSC and XRD studies confirmed the encapsulation of EFVwithin NLCs. Cytotoxicity studies (MTT assay) revealed excellent cytocompatibility (CC5013.23 ± 0.54 μg/mL). Fluorescence microscopy confirmed the efficient uptake of cationic EFVNLCs,while flow cytometry revealed time and concentration dependant uptake within THP-1cells. Cationic EFV-NLCs showed higher retention and sustained release with 2.32-fold higherpercent inhibition of HIV-1 in infected macrophages as compared to EFV solution at equimolarconcentrations. Interestingly, they demonstrated 1.23-fold superior anti-HIV efficacy over EFVloadedNLCs at equimolar concentrations. Conclusion: Cationic NLCs were capable of inhibiting the viral replication at higher limitsconsistently for 6 days suggesting successful prevention of HIV-1 replication in infectedmacrophages and thus can prove to be an attractive tool for promising anti-HIV therapy.

Optimising PLGA-PEG Nanoparticle Size and Distribution for Enhanced Drug Targeting to the Inflamed Intestinal Barrier

Oral nanomedicines are being investigated as an innovative strategy for targeted drug delivery to treat inflammatory bowel diseases. Preclinical studies have shown that nanoparticles (NPs) can preferentially penetrate inflamed intestinal tissues, allowing for targeted drug delivery. NP size is a critical factor affecting their interaction with the inflamed intestinal barrier and this remains poorly defined. In this study we aimed to assess the impact of NP particle size (PS) and polydispersity (PDI) on cell interaction and uptake in an inflamed epithelial cell model. Using 10, 55 and 100 mg/mL poly(lactic-co-glycolic acid)-polyethylene glycol (PLGA-PEG), NPs of 131, 312 and 630 nm PS, respectively, were formulated by solvent dispersion. NP recovery was optimised by differential centrifugation to yield NPs of decreased and unimodal size distribution. NP-cell interaction was assessed in healthy and inflamed caco-2 cell monolayers. Results show that NP interaction with caco-2 cells increased with increasing PS and PDI and was significantly enhanced in inflamed cells. Trypan blue quenching revealed that a significant proportion of multimodal NPs were primarily membrane bound, while monomodal NPs were internalized within cells. These results are interesting as the PS and PDI of NPs can be optimised to allow targeting of therapeutic agents to the epithelial membrane and/or intracellular targets in the inflamed intestinal epithelium.

Effect of Physico-Chemical Properties of Nanoparticles on Their Intracellular Uptake

Cellular internalization of inorganic, lipidic and polymeric nanoparticles is of great significance in the quest to develop effective formulations for the treatment of high morbidity rate diseases. Understanding nanoparticle–cell interactions plays a key role in therapeutic interventions, and it continues to be a topic of great interest to both chemists and biologists. The mechanistic evaluation of cellular uptake is quite complex and is continuously being aided by the design of nanocarriers with desired physico-chemical properties. The progress in biomedicine, including enhancing the rate of uptake by the cells, is being made through the development of structure–property relationships in nanoparticles. We summarize here investigations related to transport pathways through active and passive mechanisms, and the role played by physico-chemical properties of nanoparticles, including size, geometry or shape, core-corona structure, surface chemistry, ligand binding and mechanical effects, in influencing intracellular delivery. It is becoming clear that designing nanoparticles with specific surface composition, and engineered physical and mechanical characteristics, can facilitate their internalization more efficiently into the targeted cells, as well as enhance the rate of cellular uptake.

Enhanced In Vitro Magnetic Cell Targeting of Doxorubicin-Loaded Magnetic Liposomes for Localized Cancer Therapy

The lack of efficient targeting strategies poses significant limitations on the effectiveness of chemotherapeutic treatments. This issue also affects drug-loaded nanocarriers, reducing nanoparticles cancer cell uptake. We report on the fabrication and in vitro characterization of doxorubicin-loaded magnetic liposomes for localized treatment of liver malignancies. Colloidal stability, superparamagnetic behavior and efficient drug loading of our formulation were demonstrated. The application of an external magnetic field guaranteed enhanced nanocarriers cell uptake under cell medium flow in correspondence of a specific area, as we reported through in vitro investigation. A numerical model was used to validate experimental data of magnetic targeting, proving the possibility of accurately describing the targeting strategy and predict liposomes accumulation under different environmental conditions. Finally, in vitro studies on HepG2 cancer cells confirmed the cytotoxicity of drug-loaded magnetic liposomes, with cell viability reduction of about 50% and 80% after 24 h and 72 h of incubation, respectively. Conversely, plain nanocarriers showed no anti-proliferative effects, confirming the formulation safety. Overall, these results demonstrated significant targeting efficiency and anticancer activity of our nanocarriers and superparamagnetic nanoparticles entrapment could envision the theranostic potential of the formulation. The proposed magnetic targeting study could represent a valid tool for pre-clinical investigation regarding the effectiveness of magnetic drug targeting.

Micro- and nanoplastics - current state of knowledge with the focus on oral uptake and toxicity

The production and use of plastics has constantly increased over the last 30 years. Over one third of the plastics is used in disposables, which are discarded within three years of their production. Despite efforts towards recycling, a substantial volume of debris has accumulated in the environment and is slowly degraded to micro- and nanoplastics by weathering and aging. It has recently been discovered that these small particles can enter the food chain, as for example demonstrated by the detection of microplastic particles in honey, beer, salt, sea food and recently in mineral water. Human exposure has further been documented by the detection of plastic microparticles in human feces. Potential toxic consequences of oral exposure to small plastic particles are discussed. Due to lacking data concerning exposure, biodistribution and related effects, the risk assessment of micro- and nanoplastics is still not possible. This review focuses on the oral uptake of plastic and polymer micro- and nanoparticles. Oral exposure, particle fate, changes of particle properties during ingestion and gastrointestinal digestion, and uptake and transport at the intestinal epithelium are reviewed in detail. Moreover, the interaction with intestinal and liver cells and possibly resulting toxicity are highlighted.

Apoptosis pathway in the combined treatment of x-ray and 5-FU-loaded triblock copolymer-coated magnetic nanoparticles

Aim: In this study, the effects of ionizing radiation and 5-fluorouracil (5-FU)-loaded triblock copolymer-coated magnetic nanoparticles (NPs) on the induction of apoptosis in HT-29 and HCT-116 were investigated. Materials & methods: The percentage of apoptotic cells and alteration of the expression of apoptotic-related proteins were evaluated in treated cells by flow cytometry and western blot analysis, respectively. Results: Combination treatment with 5-FU and radiation had a stronger effect on decreasing Bcl-2 expression and increasing expression of Bax, cleaved caspase-9, cleaved caspase-3, cleaved PARP compared with each treatment alone. Conclusion: The combination of radiation and triblock copolymer-coated magnetic NPs as 5-FU drug carriers works by triggering apoptosis to improve in vitro treatment efficacy. Additional study may present the NPs as an effective approach for the treatment of colon cancer.

Preparation, evaluation, and in vitro cytotoxicity studies of artesunate-loaded glycyrrhetinic acid decorated PEG-PLGA nanoparticles

OBJECTIVE

The objective of this study was to prepare the liver targeting drug delivery system (TDDS) of artesunate (ART)-loaded polyethylene glycol (PEG)-poly(d,l-lactic-co-glycolic) acid (PLGA) nanoparticles (NPs) modified by glycyrrhetinic acid (GA), and evaluate its in vitro cytotoxicity.

SIGNIFICANCE

The GA-PEG-PLGA-ART NPs enhanced the in vitro cytotoxicity on HCC cell lines. The development of GA-PEG-PLGA NPs will greatly push the clinical applications of ART as a novel anticancer drug.

METHODS

The NPs were prepared using solvent evaporation method, and the formulation was optimized through an orthogonal design. In addition, physical properties were determined, including particle size, polydispersity index (PDI), zeta potential (ZP), morphology, drug loading capacity (LC) and encapsulation efficiency (EE), and in vitro drug release. Moreover, the in vitro cytotoxicity of NPs with three human cancer cell lines viz. HepG2, Hep3B, and SMCC-7721 was conducted using the SRB assay. Additionally, lyophilization was conducted to improve the long-term physical stability.

RESULTS

The GA-PEG-PLGA-ART NPs have spherical shape, small particle size (around 88 nm) with a narrow size distribution (PDI < 0.3), high drug LC (up to 59.3 ± 1.65%), and high EE (up to 73.13 ± 5.17%). In vitro drug release behavior showed that drugs were released from NPs in a sustained and controlled release pattern. Cytotoxicity study indicated the NPs achieved lower cancer cell survival fraction. The GA-PEG-PLGA NPs freeze-dried with 3% (w/v) of mannitol showed better effect on long-term physical stability.

CONCLUSION

The GA-PEG-PLGA-ART NPs appear as a potential liver targeted intracellular delivery platform for ART.

Liposomes Co-Encapsulating Cisplatin/Mifepristone Improve the Effect on Cervical Cancer: In Vitro and In Vivo Assessment

Cervical cancer is usually diagnosed in the later stages despite many campaigns for early detection and continues to be a major public health problem. The standard treatment is cisplatin-based chemotherapy plus radiotherapy, but patient response is far from ideal. In the research for new drugs that enhance the activity of cisplatin, different therapeutic agents have been tested, among them the antiprogestin mifepristone. Nevertheless, the efficacy of cisplatin is limited by its low specificity for tumor tissue, which causes severe side effects. Additionally, cervical tumors often become drug resistant. These problems could possibly be addressed by the use of liposome nanoparticles to encapsulate drugs and deliver them to the target. The aim of this study was to prepare liposome nanoparticles that co-encapsulate cisplatin and mifepristone, evaluate their cytotoxicity against HeLa cells and in vivo with subcutaneous inoculations of xenografts in nu/nu mice, and examine some plausible mechanisms of action. The liposomes were elaborated by the reverse-phase method and characterized by physicochemical tests. The nanoparticles had a mean particle size of 109 ± 5.4 nm and a Zeta potential of -38.7 ± 1.2 mV, the latter parameter indicating a stable formulation. These drug-loaded liposomes significantly decreased cell viability in vitro and tumor size in vivo, without generating systemic toxicity in the animals. There was evidence of cell cycle arrest and increased apoptosis. The promising results with the co-encapsulation of cisplatin/mifepristone warrant further research.

Lignin-Based Micro- and Nanomaterials and their Composites in Biomedical Applications

Lignin, as the most abundant aromatic renewable biopolymer in nature, has long been regarded as waste and simply discarded from the pulp and paper industry. In recent years, with many breakthroughs in lignin chemistry, pretreatment, and processing techniques, a lot of the inherent bioactivities of lignin, including antioxidant activities, antimicrobial activities, biocompatibilities, optical properties, and metal-ion chelating and redox activities, have been discovered and this has opened a new field not only for lignin-based materials but also for biomaterials. In this Review, the biological activities of lignin and drug/gene delivery and bioimaging applications of various types of lignin-based material are summarized. In addition, the challenges and limitations of lignin-based materials encountered during the development of biomedical applications are also discussed.

Use of mPEG-PLGA nanoparticles to improve bioactivity and hemocompatibility of streptokinase: In-vitro and in-vivo studies

Streptokinase, a clot-dissolving agent, is widely used in treatment of cardiovascular diseases such as blood clots and deep thrombosis. Streptokinase is a cost-effective drug with a short biological half-life (i.e. 15 to 30 min). In addition, due to its prokaryotic source, the immune response quickly reacts to the drug. Despite these limitations, streptokinase is still the first choice for diseases associated with thrombosis. In this work, streptokinase was encapsulated in mPEG-PLGA nanoparticles to improve its pharmacokinetic properties. The nanoparticles containing the enzyme were prepared by coaxial electrospray and their physicochemical properties, blood compatibility, circulation time and cell toxicity were evaluated. The results showed that the use of mPEG-PLGA nanoparticles to encapsulate the enzyme resulted in prolonged circulation time (up to 120 min) with a slight decrease in its activity. In vivo studies also showed that the nanoparticles containing streptokinase did not have adverse effect on blood biochemistry parameters as well as liver and kidney tissues. As a result, the mPEG-PLGA nanoparticles showed the potential for increasing the biological activity of streptokinase with no important adverse effect.

Biodegradable self-assembled nanoparticles of PEG-PLGA amphiphilic diblock copolymer as a promising stealth system for augmented vinpocetine brain delivery

Vinpocetine (VNP), a semisynthetic drug, is utilized for the treatment of cerebrovascular and memory disorders. This work aimed at formulation of biodegradable VNP long-circulating nanoparticles utilizing Polyethylene glycol methyl ether-block-poly lactide-co-glycolide (PEG-PLGA) copolymer to surmount the drug drawbacks including low oral bioavailability and short elimination half-life. VNP nanoparticles were formulated using nanoprecipitation technique. A 2⁴ factorial design was applied to assess the impact of formulation and process variables on the nanoparticles' characteristics. Statistical analysis revealed that nanoparticles size (Y₁) significantly increased with increasing PEG-PLGA amount (X₁), poly-vinyl alcohol concentration (X₂), and PLGA content (X₄), while decreased with increasing sonication time (X₃). Furthermore, the entrapment efficiency (Y₂) was positively affected by both PEG-PLGA amount and PLGA content, while negatively affected by poly-vinyl alcohol concentration. The optimized formulation prepared using 200 mg of PEG-PLGA polymer (PEG: PLGA 2000: 4,500), 0.5% polyvinyl alcohol with sonication time of 60 s achieved spherical shape with particle size of 43 nm and drug entrapment of 82%. A significant bioavailability enhancement of VNP with marked prolongation of the in vivo systemic exposure of the drug and increased brain levels has also been achieved following intraperitoneal administration in Wistar rats. Thus, the optimized formulation could be regarded as a promising stealth nanocarrier that could surmount the drug pitfalls and enhance its brain delivery.

Integration of iron oxide nanoparticles and polyaspartamide biopolymer for MRI image contrast enhancement and an efficient drug-delivery system in cancer therapy

We integrate superparamagnetic iron oxide nanoparticles with polyaspartamide (PA) biopolymer to form a biological construct that functions as a tracking, targeting and drug-delivery system for cancer diagnosis and therapy. Iron oxide nanoparticles with uniformly distributed average spherical diameters of around 10 nm and superparamagnetic characteristics play a key role in increasing the transverse 1/T ₂ relaxation rate or darkening the T ₂-weighted MR image for cancer diagnosis using MRI. In in vitro MRI testing on cancer cells, the MR images of samples with the bio-constructshow a much clearer contrast effect than those of controls. The PA biopolymer plays an essential role in enhancing the hydrophilicity and biocompatibility of the bio-construct. In addition, as a multifunctional polymer, PA is conjugated with biotin and doxorubicin (Dox) functional groups to enhance targeting and impairment of cancer cells. In in vivo testing on cancer tumors, injection with the bio-construct decreased the magnitude of cancer tumor volume growth by three times compared with that of uninjected controls. The physicochemical characteristics of the bio-construct and the roles of biotin and Dox functional groups are examined and discussed in detail.

Oral drug delivery with nanoparticles into the gastrointestinal mucosa

The oral route of protein and peptide drugs has been a popular method of drug delivery in recent years, although it is often a challenge to achieve effective drug release and minimize the barrier functions of the gastrointestinal tract. Gastrointestinal mucosa can capture and remove harmful substances; similarly, it can limit the absorption of drugs. Many drugs are effectively captured by the mucus and rapidly removed, making it difficult to control the release of drugs in the gastrointestinal tract. The use of drug carrier systems can overcome the mucosal barrier and significantly improve bioavailability. Nanoparticle drug carriers can protect the drug from degradation, transporting it to a predetermined location in the gastrointestinal tract to achieve more efficient and sustained drug delivery. It is becoming clearer that the characteristics of nanoparticles, such as particle size, charge, and hydrophobicity, are related to permeability of the mucosal barrier. This review focuses on the latest research progress of nanoparticles to penetrate the mucosal barrier, including the delivery methods of nanoparticles on the surface of gastrointestinal mucosa, and aims to summarize how successful oral nanoparticle delivery systems can overcome this biological barrier in the human body. In addition, the in vitro model based on gastrointestinal mucus is an important tool for drug research and development. Here, we discuss different types of drug delivery systems and their advantages and disadvantages in design and potential applications. Similarly, we reviewed and summarized various methods for evaluating oral nanoparticles in in vitro and in vivo models.

Recent Advances in Astaxanthin Micro/Nanoencapsulation to Improve Its Stability and Functionality as a Food Ingredient

Astaxanthin is a carotenoid produced by different organisms and microorganisms such as microalgae, bacteria, yeasts, protists, and plants, and it is also accumulated in aquatic animals such as fish and crustaceans. Astaxanthin and astaxanthin-containing lipid extracts obtained from these sources present an intense red color and a remarkable antioxidant activity, providing great potential to be employed as food ingredients with both technological and bioactive functions. However, their use is hindered by: their instability in the presence of high temperatures, acidic pH, oxygen or light; their low water solubility, bioaccessibility and bioavailability; their intense odor/flavor. The present paper reviews recent advances in the micro/nanoencapsulation of astaxanthin and astaxanthin-containing lipid extracts, developed to improve their stability, bioactivity and technological functionality for use as food ingredients. The use of diverse micro/nanoencapsulation techniques using wall materials of a different nature to improve water solubility and dispersibility in foods, masking undesirable odor and flavor, is firstly discussed, followed by a discussion of the importance of the encapsulation to retard astaxanthin release, protecting it from degradation in the gastrointestinal tract. The nanoencapsulation of astaxanthin to improve its bioaccessibility, bioavailability and bioactivity is further reviewed. Finally, the main limitations and future trends on the topic are discussed.

Targeting the Tumor Core: Hypoxia-Responsive Nanoparticles for the Delivery of Chemotherapy to Pancreatic Tumors

In pancreatic ductal adenocarcinoma (PDAC), early onset of hypoxia triggers remodeling of the extracellular matrix, epithelial-to-mesenchymal transition, increased cell survival, the formation of cancer stem cells, and drug resistance. Hypoxia in PDAC is also associated with the development of collagen-rich, fibrous extracellular stroma (desmoplasia), resulting in severely impaired drug penetration. To overcome these daunting challenges, we created polymer nanoparticles (polymersomes) that target and penetrate pancreatic tumors, reach the hypoxic niches, undergo rapid structural destabilization, and release the encapsulated drugs. In vitro studies indicated a high cellular uptake of the polymersomes and increased cytotoxicity of the drugs under hypoxia compared to unencapsulated drugs. The polymersomes decreased tumor growth by nearly 250% and significantly increased necrosis within the tumors by 60% in mice compared to untreated controls. We anticipate that these polymer nanoparticles possess a considerable translational potential for delivering drugs to solid hypoxic tumors.

Hybrid micelles based on Pt (IV) polymeric prodrug and TPGS for the enhanced cytotoxicity in drug-resistant lung cancer cells

Multidrug resistance (MDR) is a primary cause of failure in oncotherapy and interest is growing in the design of multi-stimuli responsive nano-carriers to synergistically deliver chemotherapeutic agents and P-gp inhibitors to reverse MDR. The hybrid micelles based on a Platinum (IV)-coordinate polymeric prodrugs and TPGS were developed to improve chemotherapy and reduce side effects. The pH/redox dual-sensitive polymers were synthesized by condensation polymerization using ortho ester monomer and diamminedichlorodisuccinatoplatinum (DSP). The hybrid micelles possessed uniform size (38 nm) and displayed good stability in various physiological conditions. In contrast, in vitro drug release profiles indicated that these micelles could be completely depolymerized under acidic and reducing environment, thereby more than 80 % cisplatin were released within 12 h at pH 5.0 plus 10 mM DTT. More importantly, a large amount of TPGS released simultaneously could effectively inhibit the function of drug efflux pumps, which significantly enhanced the cytotoxicity of cisplatin against A549/DDP cells. The growth inhibition rate of micelles on A549/DDP multicellular spheroids was 79.5 %, while that of free cisplatin was only 6.8 %. Therefore, these hybrid micelles are promising in overcoming tumor MDR and worth doing further research in vivo and extend to other therapeutic agents.

Strategies to enhance oral delivery of amphotericin B: a comparison of uncoated and enteric-coated nanostructured lipid carriers

The oral delivery of amphotericin B (AmB) has remained a challenge due to its low solubility, permeability, and instability in gastric acidic pH. To solve these issues, herein, we reported a novel approach of using nanostructured lipid carriers (NLCs) and NLCs coating with Eudragit^®L100-55 (Eu-NLCs) for the oral delivery of AmB. This study aimed to compare their ability in protecting the drug from degradation in gastrointestinal fluids and permeation enhancement in Caco-2 cells. Uncoated NLCs and Eu-NLCs possessed a mean particle size of ∼180 and ∼550 nm, with a zeta potential of ∼-30 and ∼-50 mV, respectively. Both NLCs demonstrated an AmB entrapment efficiency up to ∼75%. They possessed significantly greater AmB water solubility than the free drug by up to 10-fold. In fasted state simulated gastric fluid, Eu-NLCs provided significantly greater AmB protection from acidic degradation than uncoated NLCs. In fasted state simulated intestinal fluid, both uncoated and Eu-NLCs showed a fast release characteristic. Caco-2 cells permeation studies revealed that uncoated NLCs provided significantly higher apparent permeation coefficient (P _app) value than Eu-NLCs. Moreover, after 6 months of storage at 4 °C in the absence of light, the physicochemical stabilities of the lyophilized uncoated and Eu-NLCs could be maintained. In conclusion, the developed NLCs and Eu-NLCs could be a potential drug delivery system in improving the oral bioavailability of AmB.

Effects of core titanium crystal dimension and crystal phase on ROS generation and tumour accumulation of transferrin coated titanium dioxide nanoaggregates

Radionuclide-stimulated therapy (RaST), which is enhanced by Cherenkov radiation, has enabled deep tissue stimulation of UV photosensitizers, providing a new path for cancer treatment. Previous reports have shown UV-active titanium dioxide (TiO₂) nanoparticles (NPs) modified with transferrin inhibit tumour growth after orthogonal treatment with Cherenkov radiation-emitting radionuclides such as ¹⁸F-fluorodeoxyglucose (FDG). However, poor understanding of TiO₂ NP parameters on reactive oxygen species (ROS) generation and particle distribution limits effective therapy. Here we sought to delineate the effects of crystal phase and core TiO₂ crystal dimension (cTd) on ROS production and particle morphology. We prepared Transferrin (Tf)-TiO₂ nanoaggregates (NAGs) using solvothermally synthesized cTd sizes from 5 to 1000 nm diameter and holo- or apo-transferrin. Holo-transferrin was unable to stabilize TiO₂ NPs while apo-transferrin stabilized TiO₂ into uniform nanoaggregates (NAGs), which were invariant with differing cTd, averaging 116 ± 1.04 nm for cTds below 100 nm. ROS production increased from 5 to 25 nm cTd, attaining a peak at 25 nm before decreasing with larger sizes. The supra-25 nm ROS production decrease was partially driven by a ~1/r ³ surface area decline. Additionally, amorphous TiO₂ of equal core size exhibited a 2.6-fold increase in ROS production compared to anatase NAGs, although limited stability halted further use. Although both 5 and 25 nm anatase cTds formed similarly sized NAGs, 5 nm anatase showed a four-fold higher tumour-to-muscle ratio than the 25 nm NPs in tumour-bearing mice, demonstrating the intricate relationships between physical and biological properties of NAGs. The combined in vivo and ROS results demonstrate that anatase crystals and cTd size of 25 nm or less are ideal particle parameters to balance biodistribution with ROS production efficiency.

Ciprofloxacin Loaded Nanostructured Lipid Carriers Incorporated into In-Situ Gels to Improve Management of Bacterial Endophthalmitis

Bacterial endophthalmitis (BE) is a potentially sight-threatening inflammatory reaction of the intraocular fluids or tissues caused by bacteria. Ciprofloxacin (CIP) eye drops are prescribed as first-line therapy in BE. However, frequent administration is necessary due to precorneal loss and poor ocular bioavailability. The objective of the current research was to prepare CIP containing nanostructured lipid carriers (CIP-NLCs) loaded an in situ gel system (CIP-NLC-IG) for topical ocular administration for enhanced and sustained antibacterial activity in BE treatment. CIP-NLCs were prepared by the hot homogenization method and optimized based on physicochemical characteristics and physical stability. The optimized CIP-NLC formulation was converted into CIP-NLC-IG with the addition of gellan gum as a gelling agent. Furthermore, optimized CIP-NLC and CIP-NLC-IG were evaluated for in vitro release and ex vivo transcorneal permeation studies, using commercial CIP ophthalmic solution (CIP-C) as the control. The optimized CIP-NLC formulation showed particle size, polydispersity index, zeta potential, assay and entrapment efficiency of 193.1 ± 5.1 nm, 0.43 ± 0.01, -32.5 ± 1.5 mV, 99.5 ± 5.5 and 96.3 ± 2.5%, respectively. CIP-NLC-IG with 0.2% w/v gellan gum showed optimal viscoelastic characteristics. The in vitro release studies demonstrated sustained release of CIP from CIP-NLC and CIP-NLC-IG formulations over a 24 h period. Transcorneal flux and permeability increased 4 and 3.5-fold, and 2.2 and 1.9-fold from CIP-NLC and CIP-NLC-IG formulations, respectively, when compared to CIP-C. The results demonstrate that CIP-NLC-IG could be considered as an alternate delivery system to prolong the residence time on the ocular surface after topical administration. Thus, the current CIP ophthalmic formulations may exhibit improved ocular bioavailability and prolonged antibacterial activity, which may improve therapeutic outcomes in the treatment of BE.

Systematic Evaluation of PKH Labelling on Extracellular Vesicle Size by Nanoparticle Tracking Analysis

Extracellular vesicles (EVs) are membrane vesicles secreted by cells and can modulate biological activities by transferring their content following uptake into recipient cells. Labelling of EVs is a commonly used technique for understanding their cellular targeting and biodistribution. A reliable fluorescent technique needs to preserve the size of EVs since changes in size may alter their uptake and biodistribution. Lipophilic fluorescent dye molecules such as the PKH family have been widely used for EV labelling. Here, the effect of PKH labelling on the size of EVs was systematically evaluated using nanoparticle tracking analysis (NTA), which is a widely used technique for determining the size and concentration of nanoparticles. NTA analysis showed a size increase in all the PKH labelling conditions tested. As opposed to lipophilic dye molecules, no significant shift in the size of labelled EVs was detected with luminal binding dye molecules such as 5-(and-6)-carboxyfluorescein diacetate succinimidyl ester (CFDA-SE, hereinafter CFSE). This finding suggests that PKH labelling may not be a reliable technique for the tracking of EVs.

Copolymeric Micelles Overcome the Oral Delivery Challenges of Amphotericin B

Classified as a Biopharmaceutical Classification System (BCS) class IV drug, amphotericin B (AmB) has low aqueous solubility and low permeability leading to low oral bioavailability. To improve these limitations, this study investigated the potential of AmB-loaded polymeric micelles (AmB-PM) to increase intestinal absorption. AmB-PM were prepared with polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol copolymer (Soluplus^®) as a polymeric carrier and used a modified solvent diffusion and microfluidics (NanoAssemblr^®) method. AmB-PM have a mean particle size of ~80 nm and are mono-disperse with a polydispersity index <0.2. The entrapment efficiency of AmB was up to 95% and achieved with a high drug loading up to ~20% (w/w) with a total amount of incorporated drug of 1.08 ± 0.01 mg/mL. Importantly, compared to free drug, AmB-PM protected AmB from degradation in an acidic (simulated gastric) environment. Viability studies in Caco-2 cells confirmed the safety/low toxicity of AmB-PM. In vitro cellular absorption studies confirmed that AmB-PM increased AmB uptake in Caco-2 cells 6-fold more than free AmB (i.e., 25% compared with 4% within 30 min). Furthermore, the permeability of AmB across Caco-2 monolayers was significantly faster (2-fold) and more pronounced for AmB-PM in comparison to free drug (3.5-fold increase). Thus, the developed AmB-PM show promise as a novel oral delivery system for AmB and justifies further investigation.

The plastic brain: neurotoxicity of micro- and nanoplastics

Given the global abundance and environmental persistence, exposure of humans and (aquatic) animals to micro- and nanoplastics is unavoidable. Current evidence indicates that micro- and nanoplastics can be taken up by aquatic organism as well as by mammals. Upon uptake, micro- and nanoplastics can reach the brain, although there is limited information regarding the number of particles that reaches the brain and the potential neurotoxicity of these small plastic particles.

Earlier studies indicated that metal and metal-oxide nanoparticles, such as gold (Au) and titanium dioxide (TiO₂) nanoparticles, can also reach the brain to exert a range of neurotoxic effects. Given the similarities between these chemically inert metal(oxide) nanoparticles and plastic particles, this review aims to provide an overview of the reported neurotoxic effects of micro- and nanoplastics in different species and in vitro. The combined data, although fragmentary, indicate that exposure to micro- and nanoplastics can induce oxidative stress, potentially resulting in cellular damage and an increased vulnerability to develop neuronal disorders. Additionally, exposure to micro- and nanoplastics can result in inhibition of acetylcholinesterase activity and altered neurotransmitter levels, which both may contribute to the reported behavioral changes.

Currently, a systematic comparison of the neurotoxic effects of different particle types, shapes, sizes at different exposure concentrations and durations is lacking, but urgently needed to further elucidate the neurotoxic hazard and risk of exposure to micro- and nanoplastics.

Theranostic Designed Near-Infrared Fluorescent Poly (Lactic-co-Glycolic Acid) Nanoparticles and Preliminary Studies with Functionalized VEGF-Nanoparticles

Poly-lactic-co-glycolic acid nanoparticles (PLGA-NPs) were approved by the Food and Drug Administration (FDA) for drug delivery in cancer. The enhanced permeability and retention (EPR) effect drives their accumulation minimizing the side effects of chemotherapeutics. Our aim was to develop a new theranostic tool for cancer diagnosis and therapy based on PLGA-NPs and to evaluate the added value of vascular endothelial growth factor (VEGF) for enhanced tumor targeting. In vitro and in vivo properties of PLGA-NPs were tested and compared with VEGF-PLGA-NPs. Dynamic light scattering (DLS) was performed to evaluate the particle size, polydispersity index (PDI), and zeta potential of both preparations. Spectroscopy was used to confirm the absorption spectra in the near-infrared (NIR). In vivo, in BALB/c mice bearing a syngeneic tumor in the right thigh, intravenously injected PLGA-NPs showed a high target-to-muscle ratio (4.2 T/M at 24 h post-injection) that increased over time, with a maximum uptake at 72 h and a retention of the NPs up to 240 h. VEGF-PLGA-NPs accumulated in tumors 1.75 times more than PLGA-NPs with a tumor-to-muscle ratio of 7.90 ± 1.61 (versus 4.49 ± 0.54 of PLGA-NPs). Our study highlights the tumor-targeting potential of PLGA-NPs for diagnostic and therapeutic applications. Such NPs can be conjugated with proteins such as VEGF to increase accumulation in tumor lesions.

Lipid Chemical Structure Modulates the Disruptive Effects of Nanomaterials on Membrane Models

Understanding the mechanisms by which engineered nanomaterials disrupt the cell plasma membrane is crucial in advancing the industrial and biomedical applications of nanotechnology. While the role of nanoparticle properties in inducing membrane damage has received significant attention, the role of the lipid chemical structure in regulating such interactions is less explored. Here, we investigated the role of the lipid chemical structure in the disruption of lipid vesicles by unmodified silica, carboxyl-modified silica, and unmodified polystyrene nanoparticles (50 nm). The role of the lipid headgroup was examined by comparing nanoparticle effects on vesicles composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) vs an inverse phosphocholine (PC) with the same acyl chain structure. The role of acyl chain saturation was examined by comparing nanoparticle effects on saturated vs unsaturated PCs and sphingomyelins. Nanoparticle effects on PCs (glycerol backbone) vs sphingomyelins (sphingosine backbone) were also examined. Results showed that the lipid headgroup, backbone, and acyl chain saturation affect nanoparticle binding to and disruption of the membranes. A low headgroup tilt angle and the presence of a trimethylammonium moiety at the vesicle surface are required for unmodified nanoparticles to induce membrane disruption. Lipid backbone structure significantly affects nanoparticle-membrane interactions, with carboxyl-modified particles only disrupting lipids containing cis unsaturation and a sphingosine backbone. Acyl chain saturation makes vesicles more resistant to particles by increasing lipid packing in vesicles, impeding molecular interactions. Finally, nanoparticles were capable of changing the lipid packing, resulting in pore formation in the process. These observations are important in interpreting nanoparticle toxicity to biological membranes.

Magnetic nanoparticles double wrapped into cross-linked salep/PEGylated carboxymethyl cellulose; a biocompatible nanocarrier for pH-triggered release of doxorubicin

A magnetic nanocarrier was synthesized in which Fe3O4 nanoparticles were encapsulated into double layers of polysaccharide shells. The first shell, which was composed of cross-linked salep polysaccharide, contained multiple nitrogen atoms in its structure and provided numerous sites for multiple functionalization. A fluorescence dye and doxorubicin, as widely used chemotherapy agent, were easily attached to the first shell and then a second shell of PEGylated carboxymethyl cellulose enveloped the drug loaded carrier to enhance its biocompatibility and regulates the drug release behavior. The results of drug loading and release behavior showed that the resulting nanocarrier can carry large amounts of drug molecules and a remarkable pH-sensitive release was observed in vitro. The hemolysis and coagulation assays proved the biocompatibility of nanocarrier toward red blood cells and the MTT experiments confirmed that the drug loaded nanocarrier is highly toxic for MCF-7 cancer cells while the unloaded nanocarrier was almost nontoxic. Further flow cytometry experiments and confocal microscopy demonstrated that the double layered magnetic nanocarrier can penetrate into the cells and efficiently release the drug molecules into the cell nucleus. Moreover, the results of MRI experiments performed on the nanocarrier showed that it can be serve as a negative MRI contrast agent.

Brain uptake and accumulation of new levofloxacin-doxycycline combination through the use of solid lipid nanoparticles: Formulation; Optimization and in-vivo evaluation

The objective of this study is to investigate the feasibility of delivery of novel levofloxacin/ doxycycline (LEVO/DOX) combination to the brain by intranasal route to achieve a significant local concentration in the brain and a direct nose-to-brain pathway. Solid lipid nanoparticles (SLN) were selected as a drug carrier and employed Box-Behnken design for optimizing LEVO/DOX-SLN to achieve minimum particle size and maximum apparent entrapment efficiency (EE). SLNs were prepared by hot emulsification and characterized. In vitro release of optimized formulations showed prolonged drug release from the optimized formulation. The results of pharmacokinetic study of the optimized SLN-HPMC gel in plasma and brain revealed significant increase in the brain peak concentration (420, 315 ng/g), the AUC _0-360 min (57130 and 48693.13 ng. min/g) in comparison to intranasal LEVO/DOX free solution with the values of (160, 120) ng/g, (36850, 27637.5 ng⋅min/g) for LEVO and DOX, respectively. The optimized LD-SLN-HPMC gel gave a drug-targeting efficiency (DTE %) of 149.815 and 161.969 for LEVO and DOX, respectively, in comparison to the intravenous route. Moreover, the optimized formulation had a direct transport percentage (DTP %) of 33.285 and 40.236 for LEVO and DOX, respectively, which indicates a significant contribution of direct nose-to-brain pathway in brain drug delivery.

Size, shape, and flexibility influence nanoparticle transport across brain endothelium under flow

Nanoparticle-based therapeutic formulations are being increasingly explored for the treatment of various ailments. Despite numerous advances, the success of nanoparticle-based technologies in treating brain diseases has been limited. Translational hurdles of nanoparticle therapies are attributed primarily to their limited ability to cross the blood-brain barrier (BBB), which is one of the body's most exclusive barriers. Several efforts have been focused on developing affinity-based agents and using them to increase nanoparticle accumulation at the brain endothelium. Very little is known about the role of fundamental physical parameters of nanoparticles such as size, shape, and flexibility in determining their interactions with and penetration across the BBB. Using a three-dimensional human BBB microfluidic model (μHuB), we investigate the impact of these physical parameters on nanoparticle penetration across the BBB. To gain insights into the dependence of transport on nanoparticle properties, two separate parameters were measured: the number of nanoparticles that fully cross the BBB and the number that remain associated with the endothelium. Association of nanoparticles with the brain endothelium was substantially impacted by their physical characteristics. Hard particles associate more with the endothelium compared to soft particles, as do small particles compared to large particles, and spherical particles compared to rod-shaped particles. Transport across the BBB also exhibited a dependence on nanoparticle properties. A nonmonotonic dependence on size was observed, where 200 nm particles exhibited higher BBB transport compared to 100 and 500 nm spheres. Rod-shaped particles exhibited higher BBB transport when normalized by endothelial association and soft particles exhibited comparable transport to hard particles when normalized by endothelial association. Tuning nanoparticles' physical parameters could potentially enhance their ability to cross the BBB for therapeutic applications.

Recognition Sites for Cancer-targeting Drug Delivery Systems

BACKGROUND

Target-homing drug delivery systems are now gaining significant attention for use as novel therapeutic approaches in antitumor targeting for cancer therapy. Numerous targeted drug delivery systems have been designed to improve the targeting effects because these systems can display a range of favorable properties, thus, providing suitable characteristics for clinical applicability of anticancer drugs, such as increasing the solubility, and improving the drug distribution at target sites. The majority of these targeting systems are designed with respect to differences between cancerous and normal tissues, for instance, the low pH of tumor tissues or overexpressed receptors on tumor cell membranes. Due to the growing number of targeting possibilities, it is important to know the tumor-specific recognition strategies for designing novel, targeted, drug delivery systems. Herein, we identify and summarize literature pertaining to various recognition sites for optimizing the design of targeted drug delivery systems to augment current chemotherapeutic approaches.

OBJECTIVE

This review focuses on the identification of the recognition sites for developing targeted drug delivery systems for use in cancer therapeutics.

METHODS

We have reviewed and compiled cancer-specific recognition sites and their abnormal characteristics within tumor tissues (low pH, high glutathione, targetable receptors, etc.), tumor cells (receptor overexpression or tumor cell membrane changes) and tumor cell organelles (nuclear and endoplasmic reticular dysregulation) utilizing existing scientific literature. Moreover, we have highlighted the design of some targeted drug delivery systems that can be used as homing tools for these recognition sites.

RESULTS AND CONCLUSION

Targeted drug delivery systems are a promising therapeutic approach for tumor chemotherapy. Additional research focused on finding novel recognition sites, and subsequent development of targeting moieties for use with drug delivery systems will aid in the evaluation and clinical application of new and improved chemotherapeutics.

PEGylation and folate conjugation effects on the stability of chitosan-tripolyphosphate nanoparticles

Chitosan-based nanoparticles (Ch-NPs) prepared via ionotropic gelation of Ch with sodium tripolyphosphate (TPP) have been widely examined as potential drug carriers. Yet, recent studies have shown these particles to be unstable in model (pH 7.2-7.4) physiological media. To this end, here we explored the possibility of improving TPP-crosslinked Ch-NP stability through chemical Ch modification. Specifically, Ch samples with either 76% or 92% degrees of deacetylation (DD) were grafted with either polyethylene glycol (PEG), a hydrophilic molecule, or folic acid (F), a hydrophobic molecule. Limited variation in dispersion light scattering intensity, particle size and apparent ζ-potential, and lack of macroscopic precipitation were chosen as analytical evidence of dispersion stability. TPP titrations were performed to determine the optimal TPP:glucosamine molar ratio for preparing particles with near 200-nm diameters, which are desirable for systemic administration of drugs, cellular uptake, and enhancing NP blood circulation. Both DD and Ch modification influenced the particle formation process and the evolution in NP size and ζ-potential upon 30-day storage in virtually salt-free water at 25 °C and 37 °C, where the NPs underwent partial aggregation (along with possible dissolution and swelling) but remained colloidally dispersed. Under model physiological (pH 7.2; 163 mM ionic strength) conditions, however (where the chitosan amine groups were largely deprotonated), the particles quickly became destabilized, evidently due to particle dissolution followed by Ch precipitation. Overall, within the degrees of substitution used for this work (~1% for PEG, and 3 and 6% for F), neither PEG nor F qualitatively improved Ch-NP stability at physiological pH 7.2 conditions. Thus, application of TPP-crosslinked Ch-NPs in drug delivery (even when Ch is derivatized with PEG or F) should likely be limited to administration routes with acidic pH (at which these NPs remain stable).

Trimethyl chitosan nanoparticles for ocular baicalein delivery: Preparation, optimization, in vitro evaluation, in vivo pharmacokinetic study and molecular dynamics simulation

To improve ocular bioavailability of baicalein (BAI), trimethyl chitosan coated lipid nanoparticles of baicalein (TMC-BAI-LNPs) were prepared, optimized and characterized. The properties of TMC-BAI-LNPs such as morphology, particle size, zeta potential and fourier transform infrared spectroscopy were investigated. Additionally, molecular dynamics simulation was applied as a new method to evaluate drug-biological membrane interactions. Transmission electron microscopy showed that the LNPs were approximately spherical in shape with a smooth surface. TMC-BAI-LNPs had a particle size of 162.8 nm, a positive surface charge with a zeta potential of 26.6 mV. The entrapment efficiency and drug loading values of BAI in the formulation were 90.65% and 2.04%, respectively. Moreover, in vitro drug release revealed that TMC-BAI-LNPs had a sustained release effect. In vivo studies indicated TMC-BAI-LNPs had no ocular irritation and the AUC of TMC-BAI-LNPs was 3.17-fold than that of the control (p < 0.01). Molecular dynamics simulation data showed that BAI had a poor membrane permeability, which limited the ocular bioavailability. The results indicated that TMC-BAI-LNPs might open up a new avenue for ocular administration. Furthermore, molecular dynamics simulation could predict permeability of drugs.

Targeting of Hepatic Macrophages by Therapeutic Nanoparticles

Hepatic macrophage populations include different types of cells with plastic properties that can differentiate into diverse phenotypes to modulate their properties in response to different stimuli. They often regulate the activity of other cells and play an important role in many hepatic diseases. In response to those pathological situations, they are activated, releasing cytokines and chemokines; they may attract circulating monocytes and exert functions that can aggravate the symptoms or drive reparation processes. As a result, liver macrophages are potential therapeutic targets that can be oriented toward a variety of aims, with emergent nanotechnology platforms potentially offering new perspectives for macrophage vectorization. Macrophages play an essential role in the final destination of nanoparticles (NPs) in the organism, as they are involved in their uptake and trafficking in vivo. Different types of delivery nanosystems for macrophage recognition and targeting, such as liposomes, solid-lipid, polymeric, or metallic nanoparticles, have been developed. Passive targeting promotes the accumulation of the NPs in the liver due to their anatomical and physiological features. This process is modulated by NP characteristics such as size, charge, and surface modifications. Active targeting approaches with specific ligands may also be used to reach liver macrophages. In order to design new systems, the NP recognition mechanism of macrophages must be understood, taking into account that variations in local microenvironment may change the phenotype of macrophages in a way that will affect the uptake and toxicity of NPs. This kind of information may be applied to diseases where macrophages play a pathogenic role, such as metabolic disorders, infections, or cancer. The kinetics of nanoparticles strongly affects their therapeutic efficacy when administered in vivo. Release kinetics could predict the behavior of nanosystems targeting macrophages and be applied to improve their characteristics. PBPK models have been developed to characterize nanoparticle biodistribution in organs of the reticuloendothelial system (RES) such as liver or spleen. Another controversial issue is the possible toxicity of non-degradable nanoparticles, which in many cases accumulate in high percentages in macrophage clearance organs such as the liver, spleen, and kidney.

Amino acid transporters: Emerging roles in drug delivery for tumor-targeting therapy

Amino acid transporters, which play a vital role in transporting amino acids for the biosynthesis of mammalian cells, are highly expressed in types of tumors. Increasing studies have shown the feasibility of amino acid transporters as a component of tumor-targeting therapy. In this review, we focus on tumor-related amino acid transporters and their potential use in tumor-targeting therapy. Firstly, the expression characteristics of amino acid transporters in cancer and their relationship with tumor growth are reviewed. Secondly, the recognition requirements are discussed, focusing on the "acid-base" properties, conformational isomerism and structural analogues. Finally, recent developments in amino acid transporter-targeting drug delivery strategies are highlighted, including prodrugs and nanocarriers, with special attention to the latest findings of molecular mechanisms and targeting efficiency of transporter-mediated endocytosis. We aim to offer related clues that might lead to valuable tumor-targeting strategies by the utilization of amino acid transporters.

Amphotericin B Loaded Nanostructured Lipid Carriers for Parenteral Delivery: Characterization, Antifungal and In vitro Toxicity Assessment

BACKGROUND

Amphotericin B (AmB) is important for the treatment of systemic fungal infections. Nowadays, only intravenous administration (IV) of AmB has been available due to its low aqueous solubility. Two forms of AmB are available. The first is Fungizone®, a mixture of AmB and sodium deoxcycholate that produces severe nephrotoxicity. The second are lipid-based formulations that reduce nephrotoxicity, but they are costly and require higher dose than Fungizone®. Thus, a cheaper delivery system with reduced AmB toxicity is required.

OBJECTIVE

To develop and characterize AmB loaded-nanostructured lipid carriers (AmB-loaded NLCs) for IV administration to reduce AmB toxicity.

METHODS

AmB-loaded NLCs with different solid lipids were prepared by the high-pressure homogenization technique. Their physicochemical properties and the drug release profile were examined. The molecular structure of AmB, antifungal and hemolysis activities of developed AmB-loaded NLCs were also evaluated.

RESULTS

AmB-loaded NLCs ~110 to ~140 nm in diameter were successfully produced with a zeta potential of ~-19 mV and entrapment efficiency of ~75%. In vitro release showed fast release characteristics. AmB-loaded NLCs could reduce the AmB molecular aggregation as evident from the absorbance ratio of the first to the fourth peak showing a partial aggregation of AmB. This result suggested that AmB-loaded NLCs could offer less nephrotoxicity compared to Fungizone®. In vitro antifungal activity of AmB-loaded NLCs showed a minimum inhibitory concentration of 0.25 µgmL-1.

CONCLUSION

AmB-loaded NLCs present high potential carriers for effective IV treatment with prolonged circulation time and reduced toxicity.

Florfenicol Binding to Molecularly Imprinted Polymer Nanoparticles in Model and Real Samples

A simple and straightforward technique for coating microplate wells with molecularly imprinted polymer nanoparticles (nanoMIPs) to develop assays similar to the enzyme-linked immunosorbent (ELISA) assay to determine and quantify florfenicol (FF) in real food samples such as liquid milk and salmon muscle is presented here. The nanoMIPs were synthesized by a solid-phase approach with an immobilized FF (template) and characterized using dynamic light scattering, a SPR-2 biosensor system and transmission electron microscopy. Immobilization of nanoMIPs was conducted by preparing a homogenous solution of FF-nanoMIPs in water mixed with polyvinyl alcohol (PVA) 0.2% (w/v) in each well of a microplate. The detection of florfenicol was achieved in competitive binding experiments with a horseradish peroxidase-florfenicol (FF-HRP) conjugate. The assay made it possible to measure FF in buffer and in real samples (liquid milk and salmon muscle) within the range of 60-80 and 90-100 ng/mL, respectively. The immobilized nanoMIPs were stored for six weeks at room temperature and at 5 °C. The results indicate good signal recovery for all FF concentrations in spiked milk samples, without any detrimental effects to their binding properties. The high affinity of nanoMIPs and the lack of a requirement for cold chain logistics make them an attractive alternative to traditional antibodies used in ELISA.

Self-Assembly Nanoparticles for Overcoming Multidrug Resistance and Imaging-Guided Chemo-Photothermal Synergistic Cancer Therapy

Background and Purpose

The development of multiple drug resistance (MDR) to chemotherapy and single modal therapy remains unsatisfied for the eradication of tumor, which are major obstacles in cancer therapy. This novel system with excellent characteristics for inhibition of P-glycoprotein (P-gp), and for near-infrared fluorescence (NIRF) imaging-guided chemo-photothermal therapy (PTT), has been identified as a promising way to MDR and achieve synergistic cancer therapy.

Methods

In this study, we successfully synthesized a multifunctional theranostic system, which was developed through FDA-approved self-assembling drugs, which contain anticancer drug doxorubicin (Dox), imaging and high photothermal conversion drug indocyanine green (ICG) and P-gp regulator TPGS (the system named T/Dox-ICG). We studied the characterization of T/Dox-ICG NPs, including the TEM, SEM, DLS, UV-vis-NIR, zeta potential, CLSM, in vitro FL imaging, in vitro photothermal effect, in vitro Dox and ICG release. We used CLSM to verify the location of intracellular distribution of Dox in SCG 7901/VCR cells, Western blot was performed to demonstrate the TPGS-mediated inhibition of P-gp. And, the cytotoxicity of materials against SCG 7901/VCR cells was studied by the MTT assay.

Results

The TEM showed the T/Dox-ICG NPs had good monodispersity with diameters of 19.03 nm, Dox and ICG could be released constantly from T/Dox-ICG NPs in vitro. In vitro cell experiments demonstrated higher Dox accumulation and retention in the nucleus. Western blot showed TPGS could obviously inhibit the expression of P-gp. In vitro cytotoxicity assay showed more significant cytotoxicity on MDR cells (SCG 7901/VCR) with only 8.75% of cells surviving.

Conclusion

MDR cancer therapy indicates that it may be important to develop a safer system that can simultaneously inhibit the drug transporters and monitor the delivery of chemotherapeutic agents, and combination therapy have raised widespread concern on tumor treatment.

An integrated vitamin E-coated polymer hybrid nanoplatform: A lucrative option for an enhanced in vitro macrophage retention for an anti-hepatitis B therapeutic prospect

A platform capable of specifically delivering an antiviral drug to the liver infected with hepatitis B is a major concern in hepatology. Vaccination has had a major effect on decreasing the emerging numbers of new cases of infection. However, the total elimination of the hepatitis B virus from the body requires prolonged therapy. In this work, we aimed to target the liver macrophages with lipid polymer hybrid nanoparticles (LPH), combining the merit of polymeric nanoparticles and lipid vesicles. The hydrophilic antiviral drug, entecavir (E), loaded LPH nanoparticles were optimized and physicochemically characterized. A modulated lipidic corona, as well as, an additional coat with vitamin E were used to extend the drug release enhance the macrophage uptake. The selected vitamin E coated LPH nanoparticles enriched with lecithin-glyceryl monostearate lipid shell exhibited high entrapment for E (80.47%), a size ≤ 200 nm for liver passive targeting, extended release over one week, proven serum stability, retained stability after refrigeration storage for 6 months. Upon macrophage uptake in vitro assessment, the presented formulation displayed promising traits, enhancing the cellular retention in J774 macrophages cells. In vivo and antiviral activity futuristic studies would help in the potential application of the ELPH in hepatitis B control.