Investigating the Intracellular Behaviors of Liposomal Nanohybrids via SERS: Insights into the Influence of Metal Nanoparticles

Advances in microscopy characterization techniques for lipid nanocarriers in drug delivery: a comprehensive review

This review paper provides an in-depth analysis of the significance of lipid nanocarriers in drug delivery and the crucial role of characterization techniques. It explores various types of lipid nanocarriers and their applications, emphasizing the importance of microscopy-based characterization methods such as light microscopy, confocal microscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The paper also delves into sample preparation, quantitative analysis, challenges, and future directions in the field. The review concludes by underlining the pivotal role of microscopy-based characterization in advancing lipid nanocarrier research and drug delivery technologies.

Poly(aspartic acid)-based self-healing hydrogel with precise antibacterial ability for rapid infected-wound repairing

The development of wound dressings with antibacterial activities and simultaneous pro-healing functions are always urgent in treating bacterial wound infection. Herein, a novel multifunctional self-healing hydrogel was designed and prepared by crosslinking quaternary ammonium/boronic acid modified poly(aspartic acid) and poly (vinyl alcohol) polymers with targeted peptide MP196- conjugated polydopamine. The formation of this hydrogel not only improves the biocompatibility of quaternary poly(aspartic acid), but also enhances antibacterial efficacy by pH-triggering dissociation under the low pH bacterial microenvironment. Moreover, precise photothermal treatment can be achieved. In vitro study suggested high synergistic antibacterial efficiency(∼100 %) under near-infrared light, significantly higher than a single antibacterial strategy (66.0-82.6 %). In vivo study suggested infected wounds treated with the hydrogel showed an optimal healing rate(92.0 %) after 7 days. The survival rate of the bacteria in the epidermal tissues was reduced to 2.3 %. Besides, the suitable self-healing property of this hydrogel facilitated its application in the diversity of wound shapes. Thus, the novel poly(aspartic acid) hydrogel might be a promising candidate for precise therapy of bacteria-infected wounds.

Glimpse into Cellular Internalization and Intracellular Trafficking of Lipid-Based Nanoparticles in Cancer Cells

Lipid-based nanoparticles as drug delivery carriers have been mainly used for delivery of anti-cancer therapeutic agents. Lipid-based nanoparticles, due to their smaller particle size and similarity to cell membranes, are readily internalized into cancer cells. Interestingly, cancer cells also overexpress receptors for specific ligands including folic acid, hyaluronic acid, and transferrin on their surface. This allows the use of these ligands for surface modification of the lipid-based nanoparticle. These modifications then allow the specific recognition of these ligand-coated nanoparticles by their receptors on cancer cells allowing the targeted gradual intracellular accumulation of the functionalized nanoplatforms. These interactions could eventually enhance the internalization of desired drugs via increasing ligand-receptor mediated cellular uptake of the nanoplatforms. The cellular internalization of the nanoplatforms also varies and depends on their physicochemical properties including particle size, zeta potential, and shape. The cellular uptake is also influenced by the types of ligand internalization pathway utilized by cells such as phagocytosis, macropinocytosis, and multiple endocytosis pathways. In this review, we will classify and discuss lipid based nanoparticles engineered to express specific ligands, and are recognized by their receptors on cancer cell, and their cellular internalization pathways. Moreover, the intracellular fate of nanoparticles decorated with specific ligands and the best internalization pathways (caveolae mediated endocytosis) for safe cargo delivery will be discussed.

The Combination of Liposomes and Metallic Nanoparticles as Multifunctional Nanostructures in the Therapy and Medical Imaging-A Review

Nanotechnology has introduced a new quality and has definitely developed the possibilities of treating and diagnosing various diseases. One of the scientists' interests is liposomes and metallic nanoparticles (LipoMNPs)-the combination of which has introduced new properties and applications. However, the field of creating hybrid nanostructures consisting of liposomes and metallic nanoparticles is relatively little understood. The purpose of this review was to compile the latest reports in the field of treatment and medical imaging using of LipoMNPs. The authors focused on presenting this issue in the direction of improving the used conventional treatment and imaging methods. Most of all, the nature of bio-interactions between nanostructures and cells is not sufficiently taken into account. As a result, overcoming the existing limitations in the implementation of such solutions in the clinic is difficult. We concluded that hybrid nanostructures are used in a very wide range, especially in the treatment of cancer and magnetic resonance imaging. There were also solutions that combine treatments with simultaneous imaging, creating a theragnostic approach. In the future, researchers should focus on the description of the biological interactions and the long-term effects of the nanostructures to use LipoMNPs in the treatment of patients.

Smart Stimuli-Responsive Liposomal Nanohybrid Systems: A Critical Review of Theranostic Behavior in Cancer

The epoch of nanotechnology has authorized novel investigation strategies in the area of drug delivery. Liposomes are attractive biomimetic nanocarriers characterized by their biocompatibility, high loading capacity, and their ability to reduce encapsulated drug toxicity. Nevertheless, various limitations including physical instability, lack of site specificity, and low targeting abilities have impeded the use of solo liposomes. Metal nanocarriers are emerging moieties that can enhance the therapeutic activity of many drugs with improved release and targeted potential, yet numerous barriers, such as colloidal instability, cellular toxicity, and poor cellular uptake, restrain their applicability in vivo. The empire of nanohybrid systems has shelled to overcome these curbs and to combine the criteria of liposomes and metal nanocarriers for successful theranostic delivery. Metallic moieties can be embedded or functionalized on the liposomal systems. The current review sheds light on different liposomal-metal nanohybrid systems that were designed as cellular bearers for therapeutic agents, delivering them to their targeted terminus to combat one of the most widely recognized diseases, cancer.

Liposome Fusion Mediated by Hydrophobic Magnetic Nanoparticles Stabilized with Oleic Acid and Modulated by an External Magnetic Field

Membrane fusion is considered relevant in countless scientific areas and biotechnological processes, ranging from vital life events to biomedicine, pharmaceuticals, and materials engineering, among others. In this study, we employed hydrophobic oleic acid (OA)-coated magnetite (Fe₃O₄) nanoparticles (MNP-OA) as a platform to induce the fusion of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine liposomes [large unilamellar vesicles (LUVs)] in a colloidal dispersion. This fusion was monitored through dynamic light scattering, turbidimetry, and fluorescence assay using the well-known Tb/dipicolinic acid (DPA) complex formation assay. MNP-OA have shown to be able to induce fusion with the mixing of liposomal inner content with direct dependence on the nanoparticle concentration added to the LUVs. Moreover, changes in the permeability of the liposome bilayer, upon the addition of MNP-OA to liposomes, were evaluated by studying the leakage of carboxyfluorescein and of the co-encapsulated Tb/DPA complex. These assays allowed us to determine that MNP-OA did not significantly modify liposome permeability during the fusion process. Transmission electron microscopy and confocal microscopy revealed that MNP-OA remained embedded in the lipid bilayer without producing membrane rupture, liposome deformation, or destruction. In addition, we evaluated the effect of applying a low-intensity magnetic field to the LUVs/MNP-OA system and observed that the nanoparticles considerably increased their fusogenic activity under this external stimulus, as well as they are capable of responding to low magnetic fields of around 0.45 mT. These results revealed the potential of hydrophobic magnetic nanoparticles, stabilized with OA, to act as a fusogen, thus representing a valuable tool for biotechnological applications.

ADAM 8 as a novel target for doxorubicin delivery to TNBC cells using magnetic thermosensitive liposomes

Metastatic breast cancer is one of the most common causes of cancer-related death in women worldwide. The transmembrane metalloprotease-disintegrin (ADAM8) protein is highly overexpressed in triple-negative breast cancer (TNBC) cells and potentiates tumor cell invasion and extracellular matrix remodeling. Exploiting the high expression levels of ADAM8 in TNBC cells by delivering anti-ADAM8 antibodies efficiently to the targeted site can be a promising strategy for therapy of TNBC. For instance, a targeted approach with the aid of ultra-high field magnetic resonance imaging (UHF-MRI) activatable thermosensitive liposomes (Lip_TS-GD) could specifically increase the intracellular accumulation of cytotoxic drugs. The surface of doxorubicin-loaded Lip_TS-GD was modified by covalent coupling of MAB1031 antibody (Lip_TS-GD-MAB) in order to target the overexpressed ADAM8 in ADAM8 positive MDA-MB-231 cells. Physicochemical characterization of these liposomes was performed using size, surface morphology and UHF-MRI imaging analysis. In vitro cell targeting was investigated by the washing and circulation method. Intracellular trafficking and lysosomal colocalization were assessed by fluorescence microscopy. Cell viability, biocompatibility and in-ovo CAM assays were performed to determine the effectiveness and safety profiles of liposome formulations. Our results show specific binding and induction of doxorubicin release after Lip_TS-GD-MAB treatment caused a higher cytotoxic effect at the cellular target site.

Lipid-Based Drug Delivery Nanoplatforms for Colorectal Cancer Therapy

Colorectal cancer (CRC) is a prevalent disease worldwide, and patients at late stages of CRC often suffer from a high mortality rate after surgery. Adjuvant chemotherapeutics (ACs) have been extensively developed to improve the survival rate of such patients, but conventionally formulated ACs inevitably distribute toxic chemotherapeutic drugs to healthy organs and thus often trigger severe side effects. CRC cells may also develop drug resistance following repeat dosing of conventional ACs, limiting their effectiveness. Given these limitations, researchers have sought to use targeted drug delivery systems (DDSs), specifically the nanotechnology-based DDSs, to deliver the ACs. As lipid-based nanoplatforms have shown the potential to improve the efficacy and safety of various cytotoxic drugs (such as paclitaxel and vincristine) in the clinical treatment of gastric cancer and leukemia, the preclinical progress of lipid-based nanoplatforms has attracted increasing interest. The lipid-based nanoplatforms might be the most promising DDSs to succeed in entering a clinical trial for CRC treatment. This review will briefly examine the history of preclinical research on lipid-based nanoplatforms, summarize the current progress, and discuss the challenges and prospects of using such approaches in the treatment of CRC.

Intracellular uptake of and sensing with SERS-active hybrid exosomes: insight into a role of metal nanoparticles

Aim: Exosomes, known as novel biocompatible vesicles, have attracted much interest. This makes it urgent to observe exosomes at the visually cellular or subcellular levels. Methods: Herein, we constructed a new kind of exosome/metal nanohybrid and employed a surface-enhanced Raman scattering technique to study the intracellular behaviors of hybrid exosomes. Results: Experimental results revealed that hybrid exosomes were internalized mainly through clathrin-mediated endocytosis and thereafter transported to lysosomes. The metal nanoparticles in the hybrid were demonstrated to have little effect on exosomal characteristics while serving as surface-enhanced Raman scattering generators. Conclusion: This study is significant for removing the barrier in designing programmable exosome/metal nanohybrids, which will greatly improve the utility of exosomal nanohybrids for therapeutics, such as multifunctional drug-delivery systems.

Polymerase chain reaction - surface-enhanced Raman spectroscopy (PCR-SERS) method for gene methylation level detection in plasma

Gene promoter hypermethylation is a vital step in tumorigenesis. This paper set out to explore the use of polymerase chain reaction - surface-enhanced Raman spectroscopy (PCR-SERS) for the detection of gene methylation levels, with a focus on cancer diagnosis. Methods: PCR with methylation independent primers were used on DNA samples to amplify target genes regardless of their methylation states. SERS was used on the obtained PCR products to generate spectra that contained peak changes belonging to CG and AT base pairs. Multiple linear regression (MLR) was then used to deconvolute the SERS spectra so that the CG/AT ratios of the sample could be obtained. These MLR results were used to calculate methylation levels of the target genes. For protocol verification, three sets of seven reference DNA solutions with known methylation levels (0%, 1%, 5%, 25%, 50%, 75%, and 100%) were analysed. Clinically, blood plasma samples were taken from 48 non-small-cell lung cancer (NSCLC) patients and 51 healthy controls. The methylation levels of the genes p16, MGMT, and RASSF1 were determined for each patient using this method. Results: Verification experiment on the mixtures with known methylation levels resulted in an error of less than 6% from the actual levels. When applied to our clinical samples, the frequency of methylation in at least one of the three target genes among the NSCLC patients was 87.5%, but this percentage decreased to 11.8% for the control group. The methylation levels of p16 were found to be significantly higher in NSCLC patients with more pack-years smoked (p=0.04), later cancer stages (p=0.03), and cancer types of squamous cell and large cell versus adenocarcinoma (p=0.03). Prediction accuracy of 88% was achieved from classification and regression trees (CART) based on methylation levels and states, respectively. Conclusion: This research showed that the PCR-SERS protocol could quantitatively measure the methylation levels of genes in plasma. The methylation levels of the genes p16, MGMT, and RASSF1 were higher in NSCLC patients than in controls.