Effect of surface charge on the size-dependent cellular internalization of liposomes

Preparation of Puerarin Long Circulating Liposomes and its Effect on Osteoporosis in Castrated Rats

Osteoporosis is a disease that causes low bone mass and deterioration of bone microarchitecture. Puerarin is a natural isoflavone compound that has been shown to possess anti-inflammatory, antioxidant and ameliorative effects on osteoporosis with less adverse reactions. However, its fast metabolism and low oral bioavailability limit its application. This study aimed to prepare d-α-tocopherol polyethylene glycol 1000 succinate (TPGS)- modified Puerarin Long Circulating Liposomes (TPGS-Puerarin-liposomes), in order to improve the oral bioavailability of puerarin, before evaluation of its pharmacological activity in vitro and in vivo. We employed film dispersion method to develop TPGS-Puerarin-liposomes before appropriate characterizations. Afterwards, we utilized in vivo imaging, pharmacokinetic analysis and in vitro drug release testing to further evaluate the in vivo and in vitro delivery efficiency. In addition, we established a castrated osteoporosis rat model to observe the changes in femur tissue structure and bone micromorphology via hematoxylin-eosin (HE) staining and Micro Computed Tomography (Micro CT). Besides, levels of oxidative stress and inflammatory indicators, as well as expression of wnt/β-catenin pathway-related proteins were detected. In terms of physiochemical properties, the respective mean particle size (PS) and zeta potential (ZP) of TPGS-Puerarin-liposomes were 76.63±0.59 nm and -25.54±0.11 mV. The liposomal formulation exhibited encapsulation efficiency (EE) of 95.08±0.25% and drug loading (DL) of 7.84±0.07%, along with excellent storage stability. Compared with free drugs, the TPGS-Puerarin-liposomes demonstrated a sustained release effect and could increase blood concentration of puerarin in rats, thereby significantly improving its bioavailability. Also, in vivo studies have confirmed potential of the liposomes to promote bone tissue targeting and accumulation of puerarin, coupled with significant improvement of the osteoporotic status. Besides, the liposomes could also reduce levels of oxidative stress and inflammatory factors in serum and bone tissue. Additionally, we discovered that TPGS-Puerarin-liposomes increased Wnt, β-catenin and T-cell factor (TCF) expressions at protein level in the wnt/β-catenin signaling pathway. This study has demonstrated the potential of TPGS-Puerarin-liposomes for treatment of osteoporosis.

Topical Nanoliposomal Collagen Delivery for Targeted Fibril Formation by Electrical Stimulation

Collagen is a complex, large protein molecule that presents a challenge in delivering it to the skin due to its size and intricate structure. However, conventional collagen delivery methods are either invasive or may affect the protein's structural integrity. This study introduces a novel approach involving the encapsulation of collagen monomers within zwitterionic nanoliposomes, termed Lip-Cols, and the controlled formation of collagen fibrils through electric fields (EF) stimulation. The results reveal the self-assembly process of Lip-Cols through electroporation and a pH gradient change uniquely triggered by EF, leading to the alignment and aggregation of Lip-Cols on the electrode interface. Notably, Lip-Cols exhibit the capability to direct the orientation of collagen fibrils within human dermal fibroblasts. In conjunction with EF, Lip-Cols can deliver collagen into the dermal layer and increase the collagen amount in the skin. The findings provide novel insights into the directed formation of collagen fibrils via electrical stimulation and the potential of Lip-Cols as a non-invasive drug delivery system for anti-aging applications.

68 Ga-labeled, imatinib encapsulated, theranostic liposomes: Formulation, characterization, and in vitro evaluation of anticancer activity

Cancer is still a global health problem. Among cancer types, breast cancer is the most frequently diagnosed one, and it causes a high mortality rate if not diagnosed in the early stages. In our study, imatinib encapsulated, nanosized, neutral/cationic liposome formulations were prepared as theranostic agents for breast cancer. After the characterization studies in which all liposomes exhibited proper profile owing to their particle size between 133 and 250 nm, polydispersity index values lower than 0.4, neutral and cationic zeta potential values, and high drug encapsulation efficiency, controlled drug release behaviors with zero-order kinetic were obtained. The higher than 90% radiolabeling efficiency values were obtained thanks to the determination of optimum radiolabeling condition (80°C temperature, 5 mCi radioactivity, and 10 min incubation period). According to the resazurin assay evaluating the cytotoxic profile of liposomes on MCF7 cells, neutral empty liposome was found as biocompatible, while both cationic liposomes (empty and drug-loaded ones) exhibited high nonspecific cytotoxicity at even low drug concentration due to the existence of stearyl amine in the formulations. However, dose-dependent cytotoxic effect and the highest cellular binding capacity were obtained by imatinib loaded neutral liposomes. In conclusion, 68 Ga-radiolabeled, imatinib-loaded, neutral, nanosized liposome formulation is the most promising one as a theranostic agent among all formulations.

Natural products in traditional Chinese medicine: molecular mechanisms and therapeutic targets of renal fibrosis and state-of-the-art drug delivery systems

Renal fibrosis (RF) is the end stage of several chronic kidney diseases. Its series of changes include excessive accumulation of extracellular matrix, epithelial-mesenchymal transition (EMT) of renal tubular cells, fibroblast activation, immune cell infiltration, and renal cell apoptosis. RF can eventually lead to renal dysfunction or even renal failure. A large body of evidence suggests that natural products in traditional Chinese medicine (TCM) have great potential for treating RF. In this article, we first describe the recent advances in RF treatment by several natural products and clarify their mechanisms of action. They can ameliorate the RF disease phenotype, which includes apoptosis, endoplasmic reticulum stress, and EMT, by affecting relevant signaling pathways and molecular targets, thereby delaying or reversing fibrosis. We also present the roles of nanodrug delivery systems, which have been explored to address the drawback of low oral bioavailability of natural products. This may provide new ideas for using natural products for RF treatment. Finally, we provide new insights into the clinical prospects of herbal natural products.

Properties and cellular uptake of photo-triggered mixed metallosurfactant vesicles intended for controlled CO delivery in gas therapy

The scientific relevance of carbon monoxide has increased since it was discovered that it is a gasotransmitter involved in several biological processes. This fact stimulated research to find a secure and targeted delivery and lead to the synthesis of CO-releasing molecules. In this paper we present a vesicular CO delivery system triggered by light composed of a synthetized metallosurfactant (TCOL10) with two long carbon chains and a molybdenum-carbonyl complex. We studied the characteristics of mixed TCOL10/phosphatidylcholine metallosomes of different sizes. Vesicles from 80 to 800 nm in diameter are mainly unilamellar, do not disaggregate upon dilution, in the dark are physically and chemically stable at 4 °C for at least one month, and exhibit a lag phase of about 4 days before they show a spontaneous CO release at 37 °C. Internalization of metallosomes by cells was studied as function of the incubation time, and vesicle concentration and size. Results show that large vesicles are more efficiently internalized than the smaller ones in terms of the percentage of cells that show TCOL10 and the amount of drug that they take up. On balance, TCOL10 metallosomes constitute a promising and viable approach for efficient delivery of CO to biological systems.

VCAM-1-binding peptide targeted cationic liposomes containing NLRP3 siRNA to modulate LDL transcytosis as a novel therapy for experimental atherosclerosis

BACKGROUND

Activation of NLRP3 inflammasome accelerates the formation of atherosclerotic plaques. Here, we evaluated the effects of inflammation on the expression of the NLRP3 inflammasome in endothelial cells (ECs).

METHODS

The effect of TNF-α on transcytosis of LDL was measured. VCAM-1 binding peptide targeting cationic liposomes (PCLs) were prepared as siRNA vectors. Methylated NLRP3 siRNA was encapsulated into the PCLs to knock down NLRP3 in vitro and in vivo. In rats with partial carotid ligation, TNF-α-induced LDL retention in the carotid artery endothelium was observed. In ApoE^-/- mice, NLRP3 siRNA-PCLs were injected intravenously to observe their effect on the formation of atherosclerosis.

RESULTS

Our results showed that TNF-α upregulated NLRP3 in ECs, promoting the assembly of the NLRP3 inflammasome and processing of pro-IL-1β into IL-1β. Moreover, TNF-α accelerated LDL transcytosis in ECs. Knockdown of NLRP3 prevented TNF-α-induced NLPR3 inflammasome/IL-1β signaling and LDL transcytosis. Using optimized cationic liposomes to encapsulate methylated NLRP3 siRNA, resulting in targeting of VCAM-1-expressing ECs, to knockdown NLRP3, TNF-α-induced NLRP3 inflammasome activation and LDL transcytosis were prevented. Using the partial carotid ligation as an atherosclerosis rat model, we found that local administration of NLRP3 siRNA-PCLs efficiently knocked down NLPR3 expression in the carotid endothelium and dramatically attenuated the deposition of atherogenic LDL in carotid ECs in TNF-α-challenged rats. Furthermore, NLRP3 siRNA-PCLs were injected intravenously in ApoE^-/- mice, resulting in reduced plaque formation.

CONCLUSION

These findings established a novel strategy for targeting the NLRP3 inflammasome using NLRP3 siRNA-PCLs to interrupt LDL transcytosis, representing a potential novel therapy for atherosclerosis.

Mannose-Anchored Nano-Selenium Loaded Nanostructured Lipid Carriers of Etravirine for Delivery to HIV Reservoirs

The present investigation aims to develop and explore mannosylated lipid-based carriers to deliver an anti-HIV drug, Etravirine (TMC) and Selenium nanoparticles (SeNPs), to the HIV reservoirs via the mannose receptor. The successful mannosylation was evaluated by the change in zeta potential and lectin binding assay using fluorescence microscopy. Electron microscopy and scattering studies were employed to study the structure and surface of the nanocarrier system. The presence of selenium at the core-shell of the nanocarrier system was confirmed by X-ray photoelectron spectroscopy and energy dispersive X-ray analysis. Further, the in vitro anti-HIV1 efficacy was assessed using HIV1 infected TZM-bl cells followed by in vivo biodistribution studies to evaluate distribution to various reservoirs of HIV. The results exhibited higher effectiveness and a significant increase in the therapeutic index as against the plain drug. The confocal microscopy and flow cytometry studies exhibited the efficient uptake of the coumarin-6 tagged respective formulations. The protective effect of nano selenium toward oxidative stress was evaluated in rats, demonstrating the potential of the lipidic nanoparticle-containing selenium in mitigating oxidative stress in all the major organs. The in vivo biodistribution assessment in rats showed a 12.44, 8.05 and 9.83-fold improvement in the brain, ovary, and lymph node biodistribution, respectively as compared with plain TMC. Delivery of such a combination via mannosylated nanostructured lipid carriers could be an efficient approach for delivering drugs to reservoirs of HIV while simultaneously reducing the oxidative stress induced by such long-term therapies by co-loading Nano-Selenium.

Model architectures for bacterial membranes

The complex composition of bacterial membranes has a significant impact on the understanding of pathogen function and their development towards antibiotic resistance. In addition to the inherent complexity and biosafety risks of studying biological pathogen membranes, the continual rise of antibiotic resistance and its significant economical and clinical consequences has motivated the development of numerous in vitro model membrane systems with tuneable compositions, geometries, and sizes. Approaches discussed in this review include liposomes, solid-supported bilayers, and computational simulations which have been used to explore various processes including drug-membrane interactions, lipid-protein interactions, host-pathogen interactions, and structure-induced bacterial pathogenesis. The advantages, limitations, and applicable analytical tools of all architectures are summarised with a perspective for future research efforts in architectural improvement and elucidation of resistance development strategies and membrane-targeting antibiotic mechanisms.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12551-021-00913-7.

Enhancing the Endocytosis of Phosphatidylserine-Containing Liposomes through Tim4 by Modulation of Membrane Fluidity

Phosphatidylserine (PS) is a unique lipid that is recognized by the endogenetic receptor, T-cell immunoglobulin mucin protein 4 (Tim4), and PS-containing liposomes have potential use in therapeutic applications. We prepared PS-containing liposomes of various lipid compositions and examined how lipid membrane fluidity affects PS recognition by Tim4 and the resulting endocytosis efficiency into Hela cells. Surface plasmon resonance and laurdan studies showed that increasing lipid membrane fluidity increased the stability of the PS-Tim4 interaction but hampered the entry of liposomes into cells. These results show that endocytosis efficiency is determined by balancing opposing forces induced by membrane fluidity. We found that inclusion of the zwitterionic helper lipid, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, into liposomes ensured efficient cellular internalization because the presence of this lipid provides an ideal balance of lipid fluidity and Tim4 affinity. The results showed that PS recognition by Tim4 and the resulting endocytosis efficiency can be maximized by modulating the membrane fluidity of liposomes by selecting a zwitterionic helper lipid. This study improves our understanding of how to rationally optimize nanotechnology for targeted drug delivery.

A Biomimetic Approach for Spatially Controlled Cell Membrane Engineering Using Fusogenic Spherical Nucleic Acid

Engineering of the cell plasma membrane using functional DNA is important for studying and controlling cellular behaviors. However, most efforts to apply artificial DNA interactions on cells are limited to external membrane surface due to the lack of suitable synthetic tools to engineer the intracellular side, which impedes many applications in cell biology. Inspired by the natural extracellular vesicle-cell fusion process, we have developed a fusogenic spherical nucleic acid construct to realize robust DNA functionalization on both external and internal cell surfaces via liposome fusion-based transport (LiFT) strategy, which enables applications including the construction of heterotypic cell assembly for programmed signaling pathway and detection of intracellular metabolites. This approach can engineer cell membranes in a highly efficient and spatially controlled manner, allowing one to build anisotropic membrane structures with two orthogonal DNA functionalities.

Computational model of silica nanoparticle penetration into tumor spheroids: Effects of methoxy and carboxy PEG surface functionalization and hyperthermia

Drug delivery to tumors suffers from poor solubility, specificity, diffusion through the tumor micro-environment and nonoptimal interactions with components of the extracellular matrix and cell surface receptors. Nanoparticles and drug-polymer complexes address many of these problems. However, large size exasperates the problem of slow diffusion through the tumor. Three-dimensional tumor spheroids are good models to evaluate approaches to mitigate these difficulties and aid in design strategies to improve the delivery of drugs to treat cancer effectively. Diffusion of drug carriers is highly dependent on cell uptake rate parameters (association/dissociation) and temperature. Hyperthermia increases molecular transport and is known to act synergistically with chemotherapy to improve treatment. This study presents a new inverse estimation approach based on Bayesian probability for estimating nanoparticle cell uptake rates from experiments. The parameters were combined with a finite element computational model of nanoparticle transport under hyperthermia conditions to explore its effect on tumor porosity, diffusion and particle binding (association and dissociation) at cell surfaces. Carboxy-PEG-silane (cPEGSi) nanoparticles showed higher cell uptake compared to methoxy-PEG-silane (mPEGSi) nanoparticles. Simulations were consistent with experimental results from Skov-3 ovarian cancer spheroids. Amorphous silica (cPEGSi) nanoparticles (58 nm) concentrated at the periphery of the tumor spheroids at 37°C but mild hyperthermia (43°C) increased nanoparticle penetration. Thus, hyperthermia may enhance cancer treatment by improving blood delivery to tumors, enhancing extravasation and penetration into tumors, trigger release of drug from the carrier at the tumor site and possibly lead to synergistic anti-cancer activity with the drug.

Colloidal and vesicular delivery system for herbal bioactive constituents

OBJECTIVES

The main objective of the present review is to explore and examine the effectiveness of currently developed novel techniques to resolve the issues which are associated with the herbal constituents/extract.

METHODS

A systematic thorough search and collection of reviewed information from Science direct, PubMed and Google Scholar databases based on various sets of key phrases have been performed. All the findings from these data have been studied and briefed based on their relevant and irrelevant information.

RESULT

Herbal drugs are gaining more popularity in the modern world due to their applications in curing various ailments with minimum toxic effects, side effect or adverse effect. However, various challenges exist with herbal extracts/plant actives such as poor solubility (water/lipid), poor permeation, lack of targeting specificity, instability in highly acidic pH, and liver metabolism, etc. Nowadays with the expansion in the technology, novel drug delivery system provides avenues and newer opportunity towards the delivery of herbal drugs with improved physical chemical properties, pharmacokinetic and pharmacodynamic. Developing nano-strategies like Polymeric nanoparticles, Liposomes, Niosomes, Microspheres, Phytosomes, Nanoemulsion and Self Nano Emulsifying Drug Delivery System, etc. imparts benefits for delivery of phyto formulation and herbal bioactives. Nano formulation of phytoconstituents/ herbal extract could lead to enhancement of aqueous solubility, dissolution, bioavailability, stability, reduce toxicity, permeation, sustained delivery, protection from enzymatic degradation, etc. CONCLUSION: Based on the above findings, the conclusion can be drawn that the nano sized novel drug delivery systems of herbal and herbal bioactives have a potential future for upgrading the pharmacological action and defeating or overcoming the issues related with these constituents. The aims of the present review was to summarize and critically analyze the recent development of nano sized strategies for promising phytochemicals delivery systems along with their therapeutic applications supported by experimental evidence and discussing the opportunities for further aspects.

Current strategies for oral delivery of BCS IV drug nanocrystals: challenges, solutions and future trends

INTRODUCTION

Oral absorption of BCS IV drug benefits little from improved dissolution. Therefore, the absorption of BCS IV drug nanocrystals 'as a whole' strategy is preferred, and structural modification of nanocrystals is required. Surface modification helps the nanocrystals maintain particle structure before drug dissolution is needed, thus enhancing the oral absorption of BCS IV drugs and promoting therapeutic effect. Here, the main challenges and solutions of oral BCS IV drug nanocrystals delivery are discussed. Moreover, strategies for nanocrystal surface modification that facilitates oral bioavailability of BCS IV drugs are highlighted, and provide insights for the innovation in oral drug delivery.

AREAS COVERED

Promising size, shape, and surface modification of nanocrystals have gained interests for application in oral BCS IV drugs.

EXPERT OPINION

Nanocrystal surface modification is a feasible method to maintain the structural integrity of nanocrystals, and the introduced materials can also be modified to integrate additional functions to further facilitate the absorption of nanocrystals. It is expected that the absorption 'as a whole' strategy of nanocrystals will provide different choices for the oral BCS IV drugs.

Progress of cationic gene delivery reagents for non-viral vector

Gene delivery systems play a vital role in gene therapy and recombinant protein production. The advantages of using gene delivery reagents for non-viral vector include the capacity to accommodate a large packaging load and their low or absent immunogenicity. Furthermore, they are easy to produce at a large scale and preserve. Gene delivery reagents for non-viral vector are commonly used for transfecting a variety of cells and tissues. It is mainly composed of liposomes and non-liposome cationic polymers. According to the different head structures used, the non-viral cationic transfection reagents include a quaternary ammonium salt, amine, amino acid or polypeptide, guanidine salt, and a heterocyclic ring. This article summarizes these approaches and developments of types and components of transfection reagents and optimization of gene delivery. The optimization of mammalian cell transient recombinant protein expression system and cationic reagents for clinical or clinical trials are also discussed.

The sixth revolution in pediatric vaccinology: immunoengineering and delivery systems

Infection is the predominant cause of mortality in early life, and immunization is the most promising biomedical intervention to reduce this burden. However, very young infants fail to respond optimally to most vaccines currently in use, especially neonates. In 2005, Stanley Plotkin proposed that new delivery systems would spur a new revolution in pediatric vaccinology, just as attenuation, inactivation, cell culture of viruses, genetic engineering, and adjuvantation had done in preceding decades. Recent advances in the field of immunoengineering, which is evolving alongside vaccinology, have begun to increasingly influence vaccine formulation design. Historically, the particulate nature of materials used in many vaccine formulations was empiric, often because of the need to stabilize antigens or reduce endotoxin levels. However, present vaccine delivery systems are rationally engineered to mimic the size, shape, and surface chemistry of pathogens, and are therefore often referred to as "pathogen-like particles". More than a decade from his original assessment, we re-assess Plotkin's prediction. In addition, we highlight how immunoengineering and advanced delivery systems may be uniquely capable of enhancing vaccine responses in vulnerable populations, such as infants. IMPACT: Immunoengineering and advanced delivery systems are leading to new developments in pediatric vaccinology. Summarizes delivery systems currently in use and development, and prospects for the future. Broad overview of immunoengineering's impact on vaccinology, catering to Pediatric Clinicians and Immunologists.

Advanced engineered nanoparticulate platforms to address key biological barriers for delivering chemotherapeutic agents to target sites

The widespread development of nanocarriers to deliver chemotherapeutics to specific tumor sites has been motivated by the lack of selective targeting during chemotherapy inducing serious side effects and low therapeutic efficacy. The utmost challenge in targeted cancer therapies is the ineffective drug delivery system, in which the drug-loaded nanocarriers are hindered by multiple complex biological barriers that compromise the therapeutic efficacy. Despite considerable progress engineering novel nanoplatforms for the delivery of chemotherapeutics, there has been limited success in a clinical setting. In this review, we identify and analyze design strategies for improved therapeutic efficacy and unique properties of nanoplatforms, including liposomes, polymeric micelles, nanogels, and dendrimers. We provide a comprehensive and integral description of key biological barriers that nanoplatforms are exposed to during their in vivo journey and discuss associated strategies to overcome these barriers based on the latest research and information available in the field. We expect this review to provide constructive information for the rational design of more effective nanoplatforms to advance precision therapies and accelerate their clinical translation.

Physicochemical Characterization of Liposomes That Mimic the Lipid Composition of Exosomes for Effective Intracellular Trafficking

Exosomes mediate communication between cells in the body by the incorporation and transfer of biological materials. To design an artificial liposome, which would mimic the lipid composition and physicochemical characteristics of naturally occurring exosomes, we first studied the physicochemical properties of exosomes secreted from HepG2 cells. The exosome stiffness obtained by atomic force microscopy was moderate. Some liposomes were then fabricated to mimic the representative reported lipid composition of exosomes. Their physicochemical properties and cellular internalization efficiencies were investigated to optimize the cellular internalization efficiency of the liposomes. A favorable internalization efficiency was obtained by incubating HeLa cells with 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)/cholesterol (Chol)/1,2-dioleoyl-sn-glycero-3-phospho-l-serine (DOPS) (40/40/20 mol %) liposomes, which have a similar stiffness and zeta potential to exosomes. A dramatic increase in internalization efficiency was demonstrated by adding DOPS to simple DSPC/Chol liposomes. We found that DOPS had a more desirable effect on cellular internalization than its saturated lipid counterpart, 1,2-distearoyl-sn-glycero-3-phospho-l-serine. Furthermore, it was shown that the phosphatidylserine-binding protein, T-cell immunoglobulin mucin protein 4, was largely involved in the intracellular transfer of DSPC/Chol/DOPS liposomes. Thus, DOPS was a key lipid to provide the appropriate stiffness, zeta potential, and membrane surface affinity of the resulting liposome. Our results may help develop efficient drug carriers aiming to internalize active substances into cells.

Barriers and Strategies of Cationic Liposomes for Cancer Gene Therapy

Cationic liposomes (CLs) have been regarded as the most promising gene delivery vectors for decades with the advantages of excellent biodegradability, biocompatibility, and high nucleic acid encapsulation efficiency. However, the clinical use of CLs in cancer gene therapy is limited because of many uncertain factors in vivo. Extracellular barriers such as opsonization, rapid clearance by the reticuloendothelial system and poor tumor penetration, and intracellular barriers, including endosomal/lysosomal entrapped network and restricted diffusion to the nucleus, make CLs not the ideal vector for transferring extrinsic genes in the body. However, the obstacles in achieving productive therapeutic effects of nucleic acids can be addressed by tailoring the properties of CLs, which are influenced by lipid compositions and surface modification. This review focuses on the physiological barriers of CLs against cancer gene therapy and the effects of lipid compositions on governing transfection efficiency, and it briefly discusses the impacts of particle size, membrane charge density, and surface modification on the fate of CLs in vivo, which may provide guidance for their preclinical studies.

Development, Characterization and In Vitro Evaluation of Paclitaxel and Anastrozole Co-Loaded Liposome

Paclitaxel (PTX) and anastrozole (ANA) have been frequently applied in breast cancer treatment. PTX is well-known for its anti-proliferative effect meanwhile ANA has just been discovered to act as an estrogen receptor α (ERα) ligand. The combination therapy of PTX and ANA is expected to improve treating efficiency, as ANA would act as a ligand binding with the ERα gene expressed in breast cancer cells and thereafter PTX would inhibit the division and cause death to those cancer cells. In this study, liposome-based nanocarriers (LP) were developed for co-encapsulation of PTX and ANA to improve the efficacy of the combined drugs in an Estrogen receptor-responsive breast cancer study. PTX-ANA co-loaded LP was prepared using thin lipid film hydration method and was characterized for morphology, size, zeta potential, drug encapsulation and in vitro drug release. In addition, cell proliferation (WST assay) and IN Cell Analyzer were used for in vitro cytotoxicity studies on a human breast cancer cell line (MCF-7). Results showed that the prepared LP and PTX-ANA-LP had spherical vesicles, with a mean particle size of 170.1 ± 13.5 nm and 189.0 ± 22.1 nm, respectively. Controlled and sustained releases were achieved at 72 h for both of the loaded drugs. The in vitro cytotoxicity study found that the combined drugs showed higher toxicity than each single drug separately. These results suggested a new approach to breast cancer treatment, consisting of the combination therapy of PTX and ANA in liposomes based on ER response.

The Phenylethanol Glycoside Liposome Inhibits PDGF-Induced HSC Activation via Regulation of the FAK/PI3K/Akt Signaling Pathway

Cistanche tubulosa is a traditional Chinese herbal medicine that is widely used to regulate immunity, and phenylethanol glycosides (CPhGs) are among the primary components responsible for this activity. However, the application of CPhGs is negatively affected by their poor absorption and low oral utilization. Targeted drug delivery is an important development direction for pharmaceutics. Previous studies have indicated that CPhGs could block the conduction of the signaling pathways in TGF-β1/smad and inhibit the activation of hepatic stellate cells (HSCs). The aim of this study was to evaluate the anti-hepatic fibrosis effect of CPhG liposomes by inhibiting HSC activation, promoting apoptosis, blocking the cell cycle, suppressing the conduction of signaling pathways in focal adhesion kinase(FAK)/phosphatidylinositol-3-kinase(PI3K)/protein kinase B(Akt), and determining their in vitro hepatoprotective activity. In vitro release studies demonstrated that CPhG liposomes have a sustained release effect compared to drug CPhGs. HSC proliferation was inhibited after treatment with the CPhG liposomes (29.45, 14.72, 7.36 µg/mL), with IC50 values of 42.54 µg/mL in the MTT assay. Different concentrations of the CPhG liposomes could inhibit HSC proliferation, promote apoptosis, and block the cell cycle. The MTT method showed an obvious inhibition of HSC proliferation after CPhG liposome and Recombinant Rat Platelet-derived growth factor-BB(rrPDGF-BB) treatment. The levels of collagen-1, metallopeptidase inhibitor 1 (TIMP-1), α smooth muscle actin (α-SMA), and phosphorylated PI3K/Akt were downregulated, and matrix metalloproteinase-1 (MMP-1) was upregulated, by pretreatment with different concentrations of CPhG liposomes. Moreover, 29.45 μg/mL of CPhG liposomes could decrease the expression of the FAK protein and the phosphorylated PI3K and Akt protein downstream of FAK by overexpression of the FAK gene. This experiment suggests that CPhG liposomes may inhibit the activation of HSCs by inhibiting FAK and then reducing the expression of phosphorylated Akt/PI3K, thereby providing new insights into the application of CPhGs for liver fibrosis.

Evaluating Nanoparticles in Preclinical Research Using Microfluidic Systems

Nanoparticles (NPs) have found a wide range of applications in clinical therapeutic and diagnostic fields. However, currently most NPs are still in the preclinical evaluation phase with few approved for clinical use. Microfluidic systems can simulate dynamic fluid flows, chemical gradients, partitioning of multi-organs as well as local microenvironment controls, offering an efficient and cost-effective opportunity to fast screen NPs in physiologically relevant conditions. Here, in this review, we are focusing on summarizing key microfluidic platforms promising to mimic in vivo situations and test the performance of fabricated nanoparticles. Firstly, we summarize the key evaluation parameters of NPs which can affect their delivery efficacy, followed by highlighting the importance of microfluidic-based NP evaluation. Next, we will summarize main microfluidic systems effective in evaluating NP haemocompatibility, transport, uptake and toxicity, targeted accumulation and general efficacy respectively, and discuss the future directions for NP evaluation in microfluidic systems. The combination of nanoparticles and microfluidic technologies could greatly facilitate the development of drug delivery strategies and provide novel treatments and diagnostic techniques for clinically challenging diseases.