Biotin-Conjugated Multilayer Poly [D,L-lactide-co-glycolide]-Lecithin-Polyethylene Glycol Nanoparticles for Targeted Delivery of Doxorubicin

Poly(d,l-lactide-co-glycolide) Surface-Anchored Biotin-Loaded Irinotecan Nanoparticles for Active Targeting of Colon Cancer

A poly(d,l-lactide-co-glycolide) (PLGA) copolymer was synthesized using the ring-opening polymerization of d,l-lactide and glycolide monomers in the presence of zinc proline complex in bulk through the green route and was well characterized using attenuated total reflectance-Fourier transform infrared, 1H and 13C nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimetry, X-ray diffraction, matrix-assisted laser desorption/ionization time-of-flight, etc. Furthermore, PLGA-conjugated biotin (PLGA-B) was synthesized using the synthesized PLGA and was employed to fabricate nanoparticles for irinotecan (Ir) delivery. These nanoparticles (PLGA-NP-Ir and PLGA-B-NP-Ir) were tested for physicochemical and biological characteristics. PLGA-B-NP-Ir exhibited a stronger cellular uptake and anticancer activity as compared to PLGA-NP-Ir in CT-26 cancer cells (log p < 0.05). The accumulation and retention of fluorescence-labeled nanoparticles were observed to be better in CT-26-inoculated solid tumors in Balb/c mice. The PLGA-B-NP-Ir-treated group inhibited tumor growth significantly more (log p < 0.001) than the untreated control, PLGA-NP-Ir, and Ir-treated groups. Furthermore, no body weight loss, hematological, and blood biochemical tests demonstrated the nanocarriers' nontoxic nature. This work presents the use of safe PLGA and the demonstration of a proof-of-concept of biotin surface attached PLGA nanoparticle-mediated active targeted Ir administration to combat colon cancer. To treat colon cancer, PLGA-B-NP-Ir performed better due to specific active tumor targeting and greater cellular uptake due to biotin.

Rapid Production of Nanoscale Liposomes Using a 3D-Printed Reactor-In-A-Centrifuge: Formulation, Characterisation, and Super-Resolution Imaging

Nanoscale liposomes have been extensively researched and employed clinically for the delivery of biologically active compounds, including chemotherapy drugs and vaccines, offering improved pharmacokinetic behaviour and therapeutic outcomes. Traditional laboratory-scale production methods often suffer from limited control over liposome properties (e.g., size and lamellarity) and rely on laborious multistep procedures, which may limit pre-clinical research developments and innovation in this area. The widespread adoption of alternative, more controllable microfluidic-based methods is often hindered by complexities and costs associated with device manufacturing and operation, as well as the short device lifetime and the relatively low liposome production rates in some cases. In this study, we demonstrated the production of liposomes comprising therapeutically relevant lipid formulations, using a cost-effective 3D-printed reactor-in-a-centrifuge (RIAC) device. By adjusting formulation- and production-related parameters, including the concentration of polyethylene glycol (PEG), temperature, centrifugation time and speed, and lipid concentration, the mean size of the produced liposomes could be tuned in the range of 140 to 200 nm. By combining selected experimental parameters, the method was capable of producing liposomes with a therapeutically relevant mean size of ~174 nm with narrow size distribution (polydispersity index, PDI ~0.1) at a production rate of >8 mg/min. The flow-through method proposed in this study has potential to become an effective and versatile laboratory-scale approach to simplify the synthesis of therapeutic liposomal formulations.

Effect of an NGR Peptide on the Efficacy of the Doxorubicin Phospholipid Delivery System

This study is a continuation of an investigation into the effect of a targeted component, a peptide with an NGR, on the properties of the previously developed doxorubicin phospholipid delivery system. The NGR peptide has an affinity for aminopeptidase N (known as the CD13 marker on the membrane surface of tumor cells) and has been extensively used to target drug delivery systems. This article presents the results of a study investigating the physical properties of the phospholipid composition with and without the peptide chain: particle size, zeta potential, stability in fluids, and dependence of doxorubicin release from nanoparticles at different pH levels (5.0, 6.5, 7.4). The cytotoxic effect of the compositions has also been shown to depend on the dose of the drug used for incubation, the presence of the targeted component in the composition, and the time of incubation time of the substances. There was a significant difference in the cytotoxic effect on HT-1080 (CD13-positive) and MCF-7 (CD13-negative) cells. Cell death pathway analysis has shown that death occurred mainly by apoptosis. We also present data on the effect of doxorubicin embedded in phospholipid nanoparticles with the targeted peptide on DNA assessed by differential pulse voltammetry, the mechanism of action being electrostatic interactions. The interactions of native dsDNA with doxorubicin encapsulated in phospholipid nanoparticles with the targeted peptide were studied electrochemically by differential pulse voltammetry. Here, we have highlighted that the targeted peptide in the doxorubicin composition moved specific interaction of the drug with dsDNA from intercalative mode to electrostatic interactions.

Review of the Delivery Kinetics of Thermosensitive Liposomes

Thermosensitive liposomes (TSL) are triggered nanoparticles that release the encapsulated drug in response to hyperthermia. Combined with localized hyperthermia, TSL enabled loco-regional drug delivery to tumors with reduced systemic toxicities. More recent TSL formulations are based on intravascular triggered release, where drug release occurs within the microvasculature. Thus, this delivery strategy does not require enhanced permeability and retention (EPR). Compared to traditional nanoparticle drug delivery systems based on EPR with passive or active tumor targeting (typically <5%ID/g tumor), TSL can achieve superior tumor drug uptake (>10%ID/g tumor). Numerous TSL formulations have been combined with various drugs and hyperthermia devices in preclinical and clinical studies over the last four decades. Here, we review how the properties of TSL dictate delivery and discuss the advantages of rapid drug release from TSL. We show the benefits of selecting a drug with rapid extraction by tissue, and with quick cellular uptake. Furthermore, the optimal characteristics of hyperthermia devices are reviewed, and impact of tumor biology and cancer cell characteristics are discussed. Thus, this review provides guidelines on how to improve drug delivery with TSL by optimizing the combination of TSL, drug, and hyperthermia method. Many of the concepts discussed are applicable to a variety of other triggered drug delivery systems.

Synthesis, characterization, and cytotoxicity of doxorubicin-loaded polycaprolactone nanocapsules as controlled anti-hepatocellular carcinoma drug release system

Background

Free doxorubicin (Dox) is used as a chemotherapeutic agent against hepatocellular carcinoma (HCC), but it results in cardiotoxicty as a major side effect. Hence, a controlled Dox drug delivery system is extremely demanded.

Methods

Dox was loaded into the non-toxic biodegradable polycaprolactone (PCL) nanocapsules using the double emulsion method. Characterization of Dox-PCL nanocapsules was done using transmission electron microscopy and dynamic light scattering. Encapsulation efficiency and drug loading capacity were quantified using UV–visible spectrophotometry. Drug release was investigated in vitro at both normal (7.4) and cancer (4.8) pHs. Cytotoxicity of Dox-PCL nanocapsules against free Dox was evaluated using the MTT test on normal (Vero) and hepatic cancer (HepG2) cell lines.

Results

Spherical nanocapsules (212 ± 2 nm) were succeffully prepared with a zeta potential of (-22.3 ± 2 mv) and a polydisperse index of (0.019 ± 0.01) with a narrow size distribution pattern. The encapsulation efficiency was (73.15 ± 4%) with a drug loading capacity of (16.88 ± 2%). Importantlly, Dox-release from nanocapsules was faster at cancer pH (98%) than at physiological pH (26%). Moreover, although Dox-PCL nanocapsules were less toxic on the normal cell line (GI 50 = 17.99 ± 8.62 µg/ml) than free Dox (GI 50 = 16.53 ± 1.06 µg/ml), the encapsulated Dox showed higher toxic effect on cancer HepG2 cells compared to that caused by the free drug (GI 50 = 2.46 ± 0.49 and 4.22 ± 0.04 µg/ml, respectively).

Conclusion

The constructed Dox-PCL nanocapsules constitute a potentially controlled anti-HCC therapy with minimal systemic exposure.

Graphical Abstract

Preparation and evaluation of liposome with ropivacaine ion-pairing in local pain management

Local analgesia is one of the most desirable methods for postoperative pain control, while the existing local anesthetics have a short duration of analgesic effect. Nano-drug carriers have been widely used in various fields and provide an excellent strategy for traditional drugs. Although the existing liposomes for local anesthetics have certain advantages, their instability and complexity of the preparation process still cannot be ignored. Here, we developed novel ropivacaine hydrochloride liposomes with improved stability and sustained release performance by combining ropivacaine hydrochloride with sodium oleate in liposomes via hydrophobic ion-pairing (HIP). The liposomes are easy to prepare, inexpensive, and suitable for mass production. The infrared (IR), particle size, and Zeta potential measurements adequately characterized the complex, which showed a diameter of 81.09 nm and a zeta potential of -83.3 mV. Animal behavioral experiments, including the hot plate test and von Frey fiber test, demonstrated that the liposome system had a prolonged analgesic effect of 2 h versus conventional liposome preparations, consistent with the results of in vitro release experiments. In addition, in vitro cytotoxicity evaluations in RAW264.7 cells and in vivo evaluations revealed the biocompatibility and safety of the ropivacaine-sodium oleate ion-paired liposome (Rop-Ole-Lipo) system as a suitable local anesthetic for local pain management. Our findings provide a new idea for the preparation of local anesthetics.

Potential Enhancement of Metformin Hydrochloride in Solidified Reverse Micellar Solution-Based PEGylated Lipid Nanoparticles Targeting Therapeutic Efficacy in Diabetes Treatment

Metformin hydrochloride (MH) is a widely used oral biguanide antihyperglycemic (antidiabetic) drug with poor bioavailability which necessitates the development of novel drug delivery systems such as PEGylated solid lipid nanoparticles for improving its therapeutic activity. The aim of this study was to formulate, characterize and evaluate in vitro and in vivo pharmacodynamic properties of metformin–loaded PEGylated solid lipid nanoparticles (PEG-SLN) for improved delivery of MH. The lipid matrices (non-PEGylated lipid matrix and PEGylated lipid matrices) used in the formulation of both non-PEGylated (J₀) and PEGylated SLNs (J₁₀, J₂₀, J₄₀) were prepared by fusion using beeswax and Phospholipon ® 90H at 7:3 ratio with or without polyethylene glycol (PEG) 4000 (0, 10, 20 and 40% w/w), respectively. Representative lipid matrices (LM and PEG-LM) were loaded with MH by fusion and then characterized by differential scanning calorimetry (DSC) and Fourier transform infrared (FT-IR) spectroscopy. The PEG-SLNs were prepared by high shear hot homogenization using the lipid matrices (5% w/w), drug (MH) (1.0% w/w), sorbitol (4% w/w) (cryoprotectant), Tween ® 80 (2% w/w) (surfactant) and distilled water (q.s to 100% w/w) (vehicle). The non-PEGylated and PEGylated SLNs (J₀, J₁₀, J₂₀, J₄₀)) were characterized with respect to encapsulation efficiency (EE%), loading capacity (LC), morphology by scanning electron microscopy (SEM), mean particle size (Z_av) and polydispersity indices (PDI) by photon correlation spectroscopy (PCS), compatibility by FT-IR spectroscopy and in vitro drug release in biorelevant medium. Thereafter, in vivo antidiabetic study was carried out in alloxanized rats’ model and compared with controls (pure sample of MH and commercial MH- Glucophage®)). Solid state characterizations indicated the amorphous nature of MH in the drug loaded-lipid matrices. The PEG-SLNs were mostly smooth and spherical nanoformulations with Z_av and PDI of 350.00 nm and 0.54, respectively, for non-PEGylated SLNs, and in the range of 386.80–783.10 nm and 0.592 to 0.752, respectively, for PEGylated SLNs. The highest EE% and LC were noted in batch J₂₀ and were 99.28% and 16.57, respectively. There was no strong chemical interaction between the drug and excipients used in the preparation of the formulations. The PEGylated SLN (batch J₄₀) exhibited the highest percentage drug released (60%) at 8 h. The PEGylated SLNs showed greater hyperglycemic control than the marketed formulation (Glucophage ®) after 24 h. This study has shown that metformin–loaded PEGylated solid lipid nanoparticles could be employed as a potential approach to improve the delivery of MH in oral diabetic management, thus encouraging further development of the formulations.

Development and evaluation of luteolin loaded pegylated bilosome: optimization, in vitro characterization, and cytotoxicity study

The present research was aimed to develop luteolin (LL) loaded pegylated bilosomes (PG-BLs) for oral delivery. The luteolin bilosomes (BLs) were prepared by the thin-film hydration method and further optimized by the Box-Behnken design (four-factors at three-levels). The prepared LL-BLs were evaluated for vesicle size (VS), PDI, zeta potential (ZP), and entrapment efficiency to select the optimized formulation. The optimized formulation was further assessed for surface morphology, drug release, gut permeation, antioxidant, and antimicrobial study. The cytotoxicity study was conducted on breast cancer cell lines (MDA-MB-231 and MCF7). The optimized formulation LL-PG-BLs-opt exhibited a VS of 252.24 ± 3.54 nm, PDI of 0.24, ZP of -32 mV with an encapsulation efficiency of 75.05 ± 0.65%. TEM study revealed spherical shape vesicles without aggregation. The DSC and XRD results revealed that LL was encapsulated into a PG-BLs matrix. LL-PG-BLs-opt exhibited a biphasic release pattern as well as significantly high permeation (p<.05) was achieved vis-a-vis LL-BL-opt and LL dispersion. The antioxidant activity result revealed 70.31 ± 3.22%, 83.76 ± 2.56%, and 96.87 ± 2.11% from LL-dispersion, LL-BLs-opt, and LL-PG-BLs-opt, respectively. Furthermore, LL-PG-BLs-opt exhibited high cell viability on both cell lines than LL-BL-opt and pure LL. The IC₅₀ value was found to be 390 µM and 510 µM against MCF7 and MDA-MB-231 cancer cells, respectively. The antimicrobial activity result exhibited LL-PG-BLs-opt had better antibacterial activity than pure LL against Staphylococcus aureus and Escherichia coli. Hence, PG-BLs might provide an efficient nano oral delivery for the management of the different diseases.

Gypenoside XLIX loaded nanoparticles targeting therapy for renal fibrosis and its mechanism

Renal fibrosis is the main pathological feature of the occurrence and development of chronic nephropathy. At present, there is no effective treatment, except for renal transplantation and dialysis. Previous studies have shown that nano-preparations can be used as a therapeutic tool to target organs. In this study, we studied the therapeutic effect and mechanism of Chinese medicine monomer Gypenoside (Gyp) XLIX on renal fibrosis and explored the targeting and therapeutic effects of polylactic acid-co-glycoside (PLGA)-Gyp XLIX nanoparticles in unilateral ureteral occlusion (UUO) kidney. Gyp XLIX and PLGA-Gyp XLIX nanoparticles were used to treat UUO mice and Human renal tubular epithelial (HK2) cells stimulated by transforming growth factor-β (TGF-β). Histopathological and molecular biological techniques were used to detect the expression of type I collagen and alpha-smooth muscle actin (α-SMA). To investigate the in vivo targeting of PLGA nanoparticles, they were loaded with 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanine iodide and injected into UUO mice. We evaluated the effect of Gyp XLIX nanoparticles on TGF-β/Smad3 pathway, a central driver for renal fibrosis in Smad-deficient HK2 cells. Fluorescence imaging showed that the PLGA nanoparticles around 120 nm could be targeted to the UUO kidney. Compared with Gyp XLIX, PLGA-Gyp XLIX nanoparticles could effectively inhibit renal fibrosis and reduce collagen deposition and reduce renal tubular necrosis. Gyp XLIX decreased the phosphorylation of Smad3, but could not further reduce the levels of type I collagen and α-SMA in Smad-deficient cells. This study opens a promising way for targeted drug treatment of renal fibrosis.

Bio-Nanocarriers for Lung Cancer Management: Befriending the Barriers

Lung cancer is a complex thoracic malignancy developing consequential to aberrations in a myriad of molecular and biomolecular signaling pathways. It is one of the most lethal forms of cancers accounting to almost 1.8 million new annual incidences, bearing overall mortality to incidence ratio of 0.87. The dismal prognostic scenario at advanced stages of the disease and metastatic/resistant tumor cell populations stresses the requisite of advanced translational interdisciplinary interventions such as bionanotechnology. This review article deliberates insights and apprehensions on the recent prologue of nanobioengineering and bionanotechnology as an approach for the clinical management of lung cancer. The role of nanobioengineered (bio-nano) tools like bio-nanocarriers and nanobiodevices in secondary prophylaxis, diagnosis, therapeutics, and theranostics for lung cancer management has been discussed. Bioengineered, bioinspired, and biomimetic bio-nanotools of considerate translational value have been reviewed. Perspectives on existent oncostrategies, their critical comparison with bio-nanocarriers, and issues hampering their clinical bench side to bed transformation have also been summarized.

Single- versus Dual-Targeted Nanoparticles with Folic Acid and Biotin for Anticancer Drug Delivery

Cancer is one of the major causes of death worldwide and its treatment remains very challenging. The effectiveness of cancer therapy significantly depends upon tumour-specific delivery of the drug. Nanoparticle drug delivery systems have been developed to avoid the side effects of the conventional chemotherapy. However, according to the most recent recommendations, future nanomedicine should be focused mainly on active targeting of nanocarriers based on ligand-receptor recognition, which may show better efficacy than passive targeting in human cancer therapy. Nevertheless, the efficacy of single-ligand nanomedicines is still limited due to the complexity of the tumour microenvironment. Thus, the NPs are improved toward an additional functionality, e.g., pH-sensitivity (advanced single-targeted NPs). Moreover, dual-targeted nanoparticles which contain two different types of targeting agents on the same drug delivery system are developed. The advanced single-targeted NPs and dual-targeted nanocarriers present superior properties related to cell selectivity, cellular uptake and cytotoxicity toward cancer cells than conventional drug, non-targeted systems and single-targeted systems without additional functionality. Folic acid and biotin are used as targeting ligands for cancer chemotherapy, since they are available, inexpensive, nontoxic, nonimmunogenic and easy to modify. These ligands are used in both, single- and dual-targeted systems although the latter are still a novel approach. This review presents the recent achievements in the development of single- or dual-targeted nanoparticles for anticancer drug delivery.

Cytotoxicity of targeted PLGA nanoparticles: a systematic review

Recent advances in nanotechnology have contributed tremendously to the development and revolutionizing of drug delivery systems in the field of nanomedicine. In particular, targeting nanoparticles based on biodegradable poly(lactic-co-glycolic acid) (PLGA) polymers have gained much interest. However, PLGA nanoparticles remain of concern for their effectiveness against cancer cells and their toxicity to normal cells. The aim of this systematic review is to identify a promising targeting PLGA nanoformulation based on the comparison study of their cytotoxicity potency in different cell lines. A literature search was conducted through the databases of Google Scholar, PubMed, ScienceDirect, Scopus and SpringerLink. The sources studied were published between 2009 and 2019, and a variety of keywords were utilized. In total, 81 manuscripts that met the inclusion and exclusion criteria were selected for analysis based on their cytotoxicity, size, zeta potential, year of publication, type of ligand, active compounds and cell line used. The half maximal inhibitory concentration (IC50) for cytotoxicity was the main measurement in this data extraction, and the SI units were standardized to μg mL-1 for a better view of comparison. This systematic review also identified that cytotoxicity potency was inversely proportional to nanoparticle size. The PLGA nanoparticles predominantly exhibited a size of less than 300 nm and absolute zeta potential ∼20 mV. In conclusion, more comprehensive and critical appraisals of pharmacokinetic, pharmacokinetic, toxicokinetic, in vivo and in vitro tests are required for the investigation of the full value of targeting PLGA nanoparticles for cancer treatment.

Dual Redox/pH-Sensitive Micelles Self-Assembled From Star-Like Amphiphilic Copolymers Based On Sucrose For Controlled Doxorubicin Delivery

Novel dual redox/pH-sensitive star-like amphiphilic sucrose-oligo(butyl fumarate) (thioglycolic acid conjugate)-SS-poly(ethylene glycol) (Suc-OBF(TGA)-SS-PEG) copolymers and their self-assembled micelles were prepared and utilized for intracellular doxorubicin delivery. Importance of changing the hydrophobic chain length on micelles properties was investigated. Results showed that the micelles with longer hydrophobic chain exhibited smaller size and were more stable in aqueous solution. The redox and pH sensitivity of the micelles was confirmed by the change of micelle diameter/diameter distribution measured by dynamic light scattering and the change of micellar morphology observed by scanning electron microscope. The micelles display a decent doxorubicin loading capacity. In vitro release studies showed that only 14.3% doxorubicin was released from doxorubicin-loaded micelles under physiological conditions in 30 h. The release of doxorubicin was accelerated at pH 5.5 or in the presence of 10 mM glutathione at pH 7.4 (46.9% and 76.9% of doxorubicin was released, respectively, in 30 h). The doxorubicin release was further expedited under pH 5.5 and 10 mM GSH conditions (91.4%). Suc-OBF(TGA)-SS-PEG micelles displayed no cytotoxicity toward HDF cells. MTT assays indicated that doxorubicin-loaded micelles had good cytotoxicity against MCF-7 cells. This work suggested that star-like amphiphilic Suc-OBF(TGA)-SS-PEG copolymer micelles may provide a promising platform for delivering doxorubicin and other hydrophobic anticancer drugs.

PEGylated Lipid Polymeric Nanoparticle-Encapsulated Acyclovir for In Vitro Controlled Release and Ex Vivo Gut Sac Permeation

Currently, pharmaceutical research is directed wide range for developing new drugs for oral administration to target disease. Acyclovir formulation is having common issues of short half-life and poor permeability, causing messy treatment which results in patient incompliance. The present study formulates a lipid polymeric hybrid nanoparticles for antiviral acyclovir (ACV) agent with Phospholipon® 90G (lecithin), chitosan, and polyethylene glycol (PEG) to improve controlled release of the drugs. The study focused on the encapsulation of the ACV in lipid polymeric particle and their sustained delivery. The formulation developed for the self-assembly of chitosan and lecithin to form a shell encapsulating acyclovir, followed by PEGylation. Optimisation was performed via Box-Behnken Design (BBD), forming nanoparticles with size of 187.7 ± 3.75 nm, 83.81 ± 1.93% drug-entrapped efficiency (EE), and + 37.7 ± 1.16 mV zeta potential. Scanning electron microscopy and transmission electron microscopy images displayed spherical nanoparticles formation. Encapsulation of ACV and complexity with other physical parameters are confirmed through analysis using Fourier transform infrared spectroscopy, differential scanning calorimetry, and X-ray diffraction. Nanoparticle produced was capable of achieving 24-h sustained release in vitro on gastric and intestinal environments. Ex vivo study proved the improvement of acyclovir's apparent permeability from 2 × 10-6 to 6.46 × 10-6 cm s-1. Acyclovir new formulation was achieved to be stable up to 60 days for controlled release of the drugs. Graphical abstract.

Stealth Coating of Nanoparticles in Drug-Delivery Systems

Nanoparticles (NPs) have emerged as a powerful drug-delivery tool for cancer therapies to enhance the specificity of drug actions, while reducing the systemic side effects. Nonetheless, NPs interact massively with the surrounding physiological environments including plasma proteins upon administration into the bloodstream. Consequently, they are rapidly cleared from the blood circulation by the mononuclear phagocyte system (MPS) or complement system, resulting in a premature elimination that will cause the drug release at off-target sites. By grafting a stealth coating layer onto the surface of NPs, the blood circulation half-life of nanomaterials can be improved by escaping the recognition and clearance of the immune system. This review focuses on the basic concept underlying the stealth behavior of NPs by polymer coating, whereby the fundamental surface coating characteristics such as molecular weight, surface chain density as well as conformations of polymer chains are of utmost importance for efficient protection of NPs. In addition, the most commonly used stealth polymers such as poly(ethylene glycol) (PEG), poly(2-oxazoline) (POx), and poly(zwitterions) in developing long-circulating NPs for drug delivery are also thoroughly discussed. The biomimetic strategies, including the cell-membrane camouflaging technique and CD47 functionalization for the development of stealth nano-delivery systems, are highlighted in this review as well.

Meta-Analysis of Nanoparticle Delivery to Tumors Using a Physiologically Based Pharmacokinetic Modeling and Simulation Approach

Numerous studies have engineered nanoparticles with different physicochemical properties to enhance the delivery efficiency to solid tumors, yet the mean and median delivery efficiencies are only 1.48% and 0.70% of the injected dose (%ID), respectively, according to a study using a nonphysiologically based modeling approach based on published data from 2005 to 2015. In this study, we used physiologically based pharmacokinetic (PBPK) models to analyze 376 data sets covering a wide range of nanomedicines published from 2005 to 2018 and found mean and median delivery efficiencies at the last sampling time point of 2.23% and 0.76%ID, respectively. Also, the mean and median delivery efficiencies were 2.24% and 0.76%ID at 24 h and were decreased to 1.23% and 0.35%ID at 168 h, respectively, after intravenous administration. While these delivery efficiencies appear to be higher than previous findings, they are still quite low and represent a critical barrier in the clinical translation of nanomedicines. We explored the potential causes of this poor delivery efficiency using the more mechanistic PBPK perspective applied to a subset of gold nanoparticles and found that low delivery efficiency was associated with low distribution and permeability coefficients at the tumor site (P < 0.01). We also demonstrate how PBPK modeling and simulation can be used as an effective tool to investigate tumor delivery efficiency of nanomedicines.

Treatment of experimental autoimmune uveoretinitis with intravitreal injection of infliximab encapsulated in liposomes

AIMS

To evaluate the safety and efficacy of intravitreal injection of liposomes encapsulating infliximab in experimental autoimmune uveoretinitis (EAU) rats.

METHODS

Liposomes containing infliximab were prepared and characterised for mean particle size, entrapment efficiency, polydispersity index (PDI) and zeta potential. In vitro release profile and the stability of infliximab-lip were evaluated. EAU rats were intravitreally injected with saline, infliximab, infliximab-lip or unloaded liposomes. Clinical signs and ocular histological sections were graded. Infliximab concentrations were determined with competitive ELISA. Safety of the intravitreal injections was evaluated by electroretinography (ERG) and histopathological examination. Retinal biodistribution and clearance of rhodamine-conjugated liposomes containing infliximab were evaluated with a laser scanning confocal microscope.

RESULTS

The mean particle size of infliximab liposomes was 351.3±58 nm and entrapment efficiency was 90.65%±2.68%. PDI and zeta potential of infliximab liposomes were 0.386 and -20.8±9.78 mV, respectively. Stability test data showed that the infliximab-lip was stable for 60 days at room temperature. In EAU rats, intravitreal injection of infliximab and infliximab-lip greatly reduced intraocular inflammation determined by clinical scores and histopathological analyses (n=4). The mean concentrations of infliximab decreased quickly in infliximab injection group and were lower than those in infliximab-lip injection group (n=4 eyes, p<0.05 after 3 days post injection). No retinal toxic effects were detected after intravitreal injection of infliximab-lip in ERG (n=4 rats, p>0.05) and histopathological sections compared with normal rats. Confocal microscopy showed that fluorescent liposomes were observed in almost every layer of the retina and remained detectable for >30 days after injection.

CONCLUSIONS

Intravitreal injection of liposomal infliximab can prolong the persistence of the drug in vitreous body and demonstrated a satisfactory safety and significant therapeutic potentials in EAU. The use of biodegradable particles for therapeutic antibody delivery may provide a promising approach for the treatment of ocular diseases.

Beyond liposomes: Recent advances on lipid based nanostructures for poorly soluble/poorly permeable drug delivery

Solid lipid nanoparticle (SLN), nanostructured lipid carriers (NLC) and hybrid nanoparticles, have gained increasing interest as drug delivery systems because of their potential to load and release drugs from the Biopharmaceutical classification system (BCS) of class II (low solubility and high permeability) and of class IV (low solubility and low permeability). Lipid properties (e.g. high solubilizing potential, biocompatibility, biotolerability, biodegradability and distinct route of absorption) contribute for the improvement of the bioavailability of these drugs for a set of administration routes. Their interest continues to grow, as translated by the number of patents being field worldwide. This paper discusses the recent advances on the use of SLN, NLC and lipid-polymer hybrid nanoparticles for the loading of lipophilic, poorly water-soluble and poorly permeable drugs, being developed for oral, topical, parenteral and ocular administration, also discussing the industrial applications of these systems. A review of the patents filled between 2014 and 2017, concerning the original inventions of lipid nanocarriers, is also provided.

Palmitoyl ascorbate and doxorubicin co-encapsulated liposome for synergistic anticancer therapy

Combination therapy with two drugs and nanoparticle-based drug delivery systems are widely applied to reduce the adverse effects of traditional treatment by chemotherapeutic drugs. Palmitoyl ascorbate (PA) as a lipophilic derivative of ascorbic acid shows the advantages in cancer treatment. The aim of the study was to prepare a doxorubicin (DOX) and PA co-loaded liposome to synergistically treat tumor and effectively alleviate the toxicity caused by DOX. The effects were evaluated by in vitro and in vivo studies. The liposomes (weight ratio of DOX to PA=1:20, DOX₁/PA₂₀-LPs) exhibited the strongest synergistic effects, combination index was 0.38, 0.56, and 0.05 in MCF-7, HepG2, and A549 cells, respectively. In vitro cellular uptake study, the intercellular concentration of DOX in DOX₁/PA₂₀-LPs was 2.5-fold greater than DOX loaded liposome, and DOX₁/PA₂₀-LPs was taken in not only by macropinocytosis, but also by clathrin-mediated endocytosis. Intracellular distribution experiment showed that DOX₁/PA₂₀-LPs efficiently concentrated in the nucleus. In vivo studies indicated that co-encapsulated liposome not only showed the strongest antitumor ability by tumor growth suppression, but also significantly enhanced the safety by the change of body weight and reduced damages to other tissues (evidenced by histopathology study). These results indicated that DOX and PA co-delivery liposome successfully enhanced the anticancer efficacy and mitigated the toxicities of DOX, which displayed potential for clinical application with enhanced safety and efficacy.

Local anesthetic effects of bupivacaine loaded lipid-polymer hybrid nanoparticles: In vitro and in vivo evaluation

PURPOSE

There is a compelling need for prolonged local anesthetic that would be used for analgesia with a single administration. However, due to the low molecular weight of local anesthetics (LA) (lidocaine, bupivacaine, procaine, dibucaine, etc), they present fast systemic absorption.

METHODS

The aim of the present study was to develop and evaluate bupivacaine lipid-polymer hybrid nanoparticles (BVC LPNs), and compared with BVC loaded PLGA nanoparticles (BVC NPs). Their morphology, particle size, zeta potential and drug loading capacity were evaluated. In vitro release study, stability and cytotoxicity were studied. In vivo evaluation of anesthetic effects was performed on animal models.

RESULTS

A facile nanoprecipitation and self-assembly method was optimized to obtain BVC LPNs, composed of PLGA, lecithin and DSPE-PEG₂₀₀₀, of ∼175nm particle size. Compared to BVC NPs, BVC LPNs exhibited prolonged in vitro release in phosphate-buffered saline (pH=7.4). Further, BVC LPNs displayed enhanced in vitro stability in 10% FBS and lower cytotoxicity (the concentration of BVC ranging from 1.0μM to 20μM). In addition, BVC LPNs exhibited significantly prolonged analgesic duration.

CONCLUSION

These results demonstrate that the LPNs could function as promising drug delivery system for overcoming the drawbacks of poor stability and rapid drug leakage, and prolonging the anesthetic effect with slight toxicity.

Novel biodegradable nanocarriers for enhanced drug delivery

With the refinement of functional properties, the interest around biodegradable materials, in biorelated applications and, in particular, in their use as controlled drug-delivery systems, increased in the last decades. Biodegradable materials are an ideal platform to obtain nanoparticles for spatiotemporal controlled drug delivery for the in vivo administration, thanks to their biocompatibility, functionalizability, the control exerted on delivery rates and the complete degradation. Their application in systems for cancer treatment, brain and cardiovascular diseases is already a consolidated practice in research, while the bench-to-bedside translation is still late. This review aims at summarizing reported applications of biodegradable materials to obtain drug-delivery nanoparticles in the last few years, giving a complete overview of pros and cons related to degradable nanomedicaments.