Efficient Intracellular Uptake Research Articles

WITHDRAWN: Folic acid Grafted, cell-penetrating peptide conjugated pH-sensitive hydrophobically modified Glycol chitosan nanoparticles for drug delivery in breast cancer

Nanocarriers are an outcome of the fast development of nanotechnology; however, delivering drugs to tumor sites effectively is still a major difficulty. A pH-responsive drug carrier with good cell penetration and targeting ability was developed to release the drug exactly to the cancer site and overcome these limitations.The drug carrier FA-TAT-HGCNPs/PTX, which is pH-responsive, uses folic acid (FA) and TAT peptide to deliver paclitaxel (PTX) for target folate-receptor-overexpressing breast cancer cells. 2-(diisopropylamino) ethyl methacrylate was connected to glycol chitosan (GC) to form HGCNPs. Then TAT and HGCNPs were conjugated and FA was grafted onto the HGCNPs’ hydroxyl group. Physicochemical characterizations of FA-TAT-HGCNPs was also evaluated. The maximum DLE and EE values of the FA-TAT-HGCNPs at pH 8.0 were 74.0 ± 2.22 % and 93.7 ± 2.8 %, respectively. FA-TAT-HGCNPs, for instance, showed stability during long-term storage and lyophilization while exhibiting pH-responsive dissociation properties. The synthesized drug carrier was characterized by FTIR, XRD, SEM, HRTEM, DLS, and Zeta analysis. MTT assay exhibited the high anticancer activity of the FA-TAT-HGCNPs/PTX against the MCF-7 cells, whereas drug-free ones are highly biocompatible. The pharmacokinetic results showed twice the bioavailability of FA-TAT-HGCNPs/PTX compared to HGCNPs/PTX. Unlike FA-HGCNPs/PTX, CLSM analysis showed that FA-TAT-HGCNPs/PTX had a significantly more efficient intracellular uptake in MCF-7 cells. These data have shown the transmembrane ability of TATpeptide,the targeting effects of folate decoration, and the synergistic interaction between them.According to these findings, PTX-loaded FA-TAT-HGCNPs offer a potentially effective nanoscale drug delivery system for the treatment of breast cancer.

Facilitated Transport of EGFR Inhibitors Plays an Important Role in Their Cellular Uptake.

Epidermal growth factor receptor (EGFR) is a transmembrane protein commonly targeted by tyrosine kinase inhibitors (TKIs) as a front-line therapy for patients with many cancers including nonsmall cell lung cancer (NSCLC). Effective treatment requires efficient intracellular drug uptake and target binding. However, despite the recent success in the development of new TKI drugs, the mechanisms of uptake for many TKIs are still poorly understood due to the difficulty in imaging and measuring nonfluorescent drug molecules at a subcellular resolution. It has previously been shown that weakly basic TKI drugs are sequestered in lysosomes. Leveraging this property, we apply hyperspectral stimulated Raman scattering imaging to directly visualize and quantify two Food and Drug Administration-approved EGFR inhibitor drugs (lapatinib and afatinib) inside living cells and the changes in their cellular uptake upon the addition of organic cation transporter inhibitors. These single-cell quantitative measurements provide new insight into the role of membrane transporters in the uptake of TKI drugs in living cells.

Bi-Functionalized Transferrin@MoS2-PEG Nanosheets for Improving Cellular Uptake in HepG2 Cells.

Pre-coating with a protein corona on the surface of nanomaterials (NMs) is an important strategy for reducing non-specific serum protein absorption while maintaining targeting specificity. Here, we present lipoic acid-terminated polyethylene glycol and transferrin bi-functionalized MoS2 nanosheets (Tf@MoS2-PEG NSs) as a feasible approach to enhance cellular uptake. Tf@MoS2-PEG NSs can maintain good dispersion stability in cell culture medium and effectively protect MoS2 NSs from oxidation in ambient aqueous conditions. Competitive adsorption experiments indicate that transferrin was more prone to bind MoS2 NSs than bovine serum albumin (BSA). It is noteworthy that single HepG2 cell uptake of Tf@MoS2-PEG presented a heterogeneous distribution pattern, and the cellular uptake amount spanned a broader range (from 0.4 fg to 2.4 fg). Comparatively, the intracellular Mo masses in HepG2 cells treated with BSA@MoS2-PEG and MoS2-PEG showed narrower distribution, indicating homogeneous uptake in the single HepG2 cells. Over 5% of HepG2 cells presented uptake of the Tf@MoS2-PEG over 1.2 fg of Mo, about three-fold that of BSA@MoS2-PEG (0.4 fg of Mo). Overall, this work suggests that Tf coating enhances the cellular uptake of MoS2 NSs and is a promising strategy for improving the intracellular uptake efficiency of cancer cells.

Phospholipid-based nanodrill technology for enhanced intracellular delivery of nano-sized cargos

Nanosized drug delivery systems typically enter the cell via endocytosis. However, a significant amount of the endocytosed cargo cannot effectively escape from the endosome, resulting in drug degradation. Therefore, there are several ongoing efforts to develop transmembrane delivery systems that could circumvent endocytosis. In this study, phospholipid nanotube nanodrills (LDs) were formed onto the surface of a human serum albumin nanoparticle via self-assembling phospholipids. The nanodrill technology enhanced the intracellular uptake efficiency of nanoparticles via energy-independent direct cell membrane permeation. The length of the nanodrills according to the DSPE-PEG to DSPC ratio was investigated both experimentally and theoretically. Our findings demonstrated that longer nanodrills were formed on the surface of the nanoparticles as the ratio of DSPC (i.e., a strongly hydrophobic lipid) in the two phospholipids increases. Moreover, the intracellular uptake efficiency increased as the length of phospholipid nanodrills increased. In addition to enhancing intracellular delivery, the phospholipid nanodrills could penetrate the extracellular matrix and enable the introduction of nanoparticles, thus highlighting the promising tissue penetration capacity of phospholipid nanodrill technology. The improved cell permeability of LD technology was demonstrated by effectively inhibiting specific genes via siRNA-based therapeutic delivery. Moreover, this approach enhanced the efficacy of chemotherapeutics against chemo-resistant cancer cells. Therefore, LD technology could be used to deliver genetic materials and chemical-based therapeutics both in vitro and in vivo.

One-Step Synthesis of Peptide-Gold Nanoclusters with Tunable Fluorescence and Enhanced Gene Delivery Efficiency.

In this study, peptide-gold nanoclusters with tunable fluorescence were prepared by a simple "one-pot" method, which were used for gene localization and delivery in vivo to achieve efficient intracellular colocalization, uptake, and transfection. The efficiency of pDNA transfection was up to 70.6%, and there was no obvious cytotoxicity. This study proves that the simple-composition and bio-friendly peptide-gold nanoclusters are promising gene delivery carriers and can provide a powerful theoretical and experimental basis for the application of peptide-metal nanocomplexes in gene delivery and other biomedicine fields.

Functional ligands for improving anticancer drug therapy: current status and applications to drug delivery systems

Conventional chemotherapy lacking target selectivity often leads to severe side effects, limiting the effectiveness of chemotherapy. Therefore, drug delivery systems ensuring both selective drug release and efficient intracellular uptake at the target sites are highly demanded in chemotherapy to improve the quality of life of patients with low toxicity. One of the effective approaches for tumor-selective drug delivery is the adoption of functional ligands that can interact with specific receptors overexpressed in malignant cancer cells. Various functional ligands including folic acid, hyaluronic acid, transferrin, peptides, and antibodies, have been extensively explored to develop tumor-selective drug delivery systems. Furthermore, cell-penetrating peptides or ligands for tight junction opening are also actively pursued to improve the intracellular trafficking of anticancer drugs. Sometimes, multiple ligands with different roles are used in combination to enhance the cellular uptake as well as target selectivity of anticancer drugs. In this review, the current status of various functional ligands applicable to improve the effectiveness of cancer chemotherapy is overviewed with a focus on their roles, characteristics, and preclinical/clinical applications.

A nanosensitizer self-assembled from oleanolic acid and chlorin e6 for synergistic chemo/sono-photodynamic cancer therapy

BackgroundSono-photodynamic therapy (SPDT) which is the combination of photodynamic therapy (PDT) and sonodynamic therapy (SDT), could exert much better anti-cancer effects than monotherapy. The combination of chemotherapy and PDT or SDT has shown great potential for cancer treatment. However, the combination of SPDT and chemotherapy for cancer treatment is rarely explored. PurposeWe utilized a natural hydrophobic anti-cancer drug oleanolic acid (OA) and a photosensitizer chlorin e6 (Ce6) through self-assembly technology to form a carrier-free nanosensitizer OC for combined chemotherapy and SPDT for cancer treatment. No studies involving using carrier-free nanomedicine for combined chemotherapy/SPDT have been reported yet. Study designAfter fully characterization of OC, the in vitro and in vivo anti-cancer activities of OC were investigated and the mechanisms of the synergistic therapeutic effects were studied. MethodsOC were synthesized through self-assembly technology and characterized by dynamic light scattering (DLS) and an atomic force microscope (AFM). Confocal microscope was used to investigate the intracellular uptake efficiency and the penetration ability of OC. The cell viability of PC9 and 4T1 cells treated with OC under laser and ultrasound (US) irradiation was determined by MTT assay. Furthermore, flow cytometry was performed to detect the reactive oxygen species (ROS) generation, loss of mitochondrial membrane potential (MMP), cell apoptosis and cell cycle arrest. Finally, the anti-tumor therapeutic efficacy of OC was investigated in orthotopic 4T1 breast tumor-bearing mouse model. ResultsOC showed an average particle size of around 100 nm with excellent light stability. OC increased more than 23 times accumulation of Ce6 in cancer cells and had strong tumor penetration ability in three-dimensional (3D) multicellular tumor spheroids (MCTSs). Compared with other therapeutic options, OC showed obvious synergistic inhibitory effects under light and US irradiation in PC9 and 4T1 cells with a significant decrease in IC50 values. Mechanism studies showed that OC could generate high ROS, induce MMP loss, and cause apoptosis and cell cycle arrest. In vivo studies also approved the synergistic therapeutic effects of OC in 4T1 mouse models. ConclusionSelf-assembled carrier-free nanosensitizer OC could be a promising therapeutic agent for synergistic chemo/sono-photodynamic therapy for cancer treatment.

Tunable multi-responsive nano-gated mesoporous silica nanoparticles as drug carriers

Tunable multi-responsive mesoporous silica nanoparticles were prepared by post-condensation/surface modification of MCM-41 nanoparticles. Surface grafting of a poly(N,N-dimethylaminoethyl methacrylate)-based polymer containing disulfide bonds was achieved by a click reaction. Chemical modification, morphological characteristics, and textural properties of the nanoparticles were studied using multiple characterization techniques such as Fourier transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, small-angle X-ray scattering, and nitrogen adsorption/desorption behavior. The nanoparticles retained the meso-structural integrity of MCM41 and particle size < 100 nm after grafting with the polymer. The pH and redox-responsive behavior of the nanoparticles were also studied. The nanoparticles possess excellent drug-loading capacity owing to their large surface area and ‘closed gate’ mechanism of the grafted polymer chains. The release profile of doxorubicin at two different pH (7.4 and 5.5) and in the presence of dithiothreitol showed a dual response behavior. The nano drug carrier device exhibited efficient intracellular uptake in cancer cells with suitable cytotoxicity and pharmacokinetic behavior, and may therefore be considered a good candidate for cancer therapy.

Self-assembled DNA nanotrains for targeted delivery of mithramycin dimers coordinated by different metal ions: Effect of binding affinity on drug loading, release and cytotoxicity

Self-assembled DNA nanostructures, as a novel type of nano-biomaterials, are widely used for smart and targeted drug delivery due to their precise structures and versatile functions. The binding affinity of drugs to DNA nanostructures plays an important role in drug loading, release and efficacy. The interaction of mithramycin (MTR) with AS1411-tethered DNA nanotrains (AS1411NTrs) in the presence of different divalent metal ions (Mg2+, Zn2+, and Mn2+) was studied by fluorescence spectroscopy, differential scanning calorimetry and viscosity measurement. The binding mode between the MTR dimers and AS1411NTrs was determined by viscosity experiment and melting temperature measurement. The thermodynamic parameters of the binding process (binding stoichiometry, binding constant, enthalpy change, entropy change and Gibbs free energy change) were determined by fluorescence spectroscopy and differential scanning calorimetry, and the effect of different metal ions on the binding was compared. The release of the MTR dimers loaded by AS1411NTrs in the absence and presence of DNase I was analyzed. The in vitro cytotoxicity of the MTR dimers to HepG2 cancer cells and L02 normal cells and their intracellular uptake efficiency were evaluated. The binding parameters were correlated with the loading, release and cytotoxicity of the MTR dimers. These studies showed that AS1411NTrs had high drug loading and sustained release effect on (MTR)2Mg2+, (MTR)2Zn2+ and (MTR)2Mn2+. This drug loading system improved the lethality to cancer cells and reduced the side effects on normal cells. This study may provide a theoretical basis for the clinical application of MTR loaded by DNA nanostructures.

Usefulness of cell-penetrating peptides and penetration accelerating sequence for nose-to-brain delivery of glucagon-like peptide-2

Neuropeptides are expected as therapeutic drug candidates for central nervous system (CNS) disorders. Intracerebroventricular (i.c.v.) administration of glucagon-like peptide-2 (GLP-2) has an antidepressant-like effect not only in depression model mice but also in treatment-resistant depression model mice. However, because i.c.v. administration is very invasive, research is progressing on brain delivery using intranasal administration as a non-invasive method. After intranasal administration of the drug, there are two routes to the brain. That of direct delivery from the paracellular route of olfactory epithelium to the brain via the olfactory bulb has been studied, and that of systemic absorption via the paracellular route of respiratory epithelium has been put to practical use. The high degree of vascularization and permeability of the nasal mucosa enables drug delivery via the paracellular route that leads to systemic delivery. Therefore, suppressing systemic absorption may increase drug delivery to brain, so we focused on the transcellular route. We created a GLP-2 derivative by adding cell-penetrating peptides (CPP) and penetration accelerating sequences (PAS), which are reported to provide efficient intracellular uptake, to GLP-2. However, to deliver GLP-2 by the transcellular route, GLP-2 must not only be taken up into cells but also move out of the cells. We investigated in vitro and in vivo function of PAS-CPP-GLP-2 to enable the translocation of GLP-2 directly from the nose to the brain. Derivatization of PAS-CPP-GLP-2 prevented its degradation. In the evaluation of intracellular dynamics, PAS-CPP-GLP-2 enhanced cellular uptake by macropinocytosis with CPP and promoted escape from endosomal vesicles by PAS. This study also showed that PAS-CPP-GLP-2 can move out of cells. Furthermore, only this PAS-CPP-GLP-2 showed an antidepression-like effect within 20 min of intranasal administration. Intranasal administered PAS-CPP-GLP-2 surprisingly showed the effect at the same dose with i.c.v. administration, but intravenous administered PAS-CPP-GLP-2 did not show the effect. These results suggested that PAS-CPP-GLP-2 can be efficiently delivered from the nose to the CNS and show a pharmacological effect, demonstrating the usefulness of PAS and CPP for nose-to-brain delivery of GLP-2.

Amphiphilic peptide dendrimer-based nanovehicles for safe and effective siRNA delivery

Small interfering RNA (siRNA)-based RNA interference has emerged as a promising therapeutic strategy for the treatment of a wide range of incurable diseases. However, the safe and effective delivery of siRNA therapeutics into the interior of target cells remains challenging. Here, we disclosed novel amphiphilic peptide dendrimers (AmPDs) that composed of hydrophobic two lipid-like alkyl chains and hydrophilic poly(lysine) dendrons with different generations (2C18-KK2 and 2C18-KK2K4) as nanovehicles for siRNA delivery. These AmPDs are able to self-assemble into supramolecular nanoassemblies that are capable of entrapping siRNA molecules into nanoparticles to protect siRNA from enzymatic degradation and promote efficient intracellular uptake without evident toxicity. Interestingly, by virtue of the optimal balance of hydrophobic lipid-like entity and hydrophilic poly(lysine) dendron generations, AmPD 2C18-KK2K4 bearing bigger hydrophilic dendron can package siRNA to form stable, but more ready to disassemble complexes, thereby resulting in more efficient siRNA releasing and better gene silencing effect in comparison with AmPD 2C18-KK2 bearing smaller dendron. Additional studies confirmed that 2C18-KK2K4 can capitalize on the advantages of lipid and peptide dendrimer vectors for effective siRNA delivery. Collectively, our AmPD-based nanocarriers indeed represent a safe and effective siRNA delivery system. Our findings also provide a new perspective on the modulation of self-assembly amphiphilic peptide dendrimers for the functional and adaptive delivery of siRNA therapeutics.

Targeted and triple therapy-based liposomes for enhanced treatment of rheumatoid arthritis.

Rheumatoid arthritis (RA) is an autoimmune disease that is currently incurable. Clinical practice has shown significant benefits of combined therapies for RA treatment. This study aims to develop and demonstrate an efficient triple therapy for RA in vitro and in vivo. Three anti-inflammatory agents, NF-κB decoy oligodeoxynucleotides (ODNs), gold nanorods (GNRs), and dexamethasone (DEX), were encapsulated into folate (FA) modified liposomes (FA-lip(DEX+GNRs/ODNs)). The FA-lip(DEX+GNRs/ODNs) showed favorable physicochemical properties and efficient intracellular uptake by inflamed macrophages. Combined with laser irradiation, FA-lip(DEX+GNRs/ODNs) greatly reduced the secretion of proinflammatory proteins and oxidative factors in vitro. In adjuvant-induced arthritis (AIA) mice, FA-lip(DEX+GNRs/ODNs) achieved prolonged and enhanced accumulation at inflamed paws. FA-lip(DEX+GNRs/ODNs)+laser treatment reduced clinical arthritis scores and serum cytokine levels and protected cartilage. In summary, the triple therapy demonstrated significantly enhanced anti-inflammatory efficacy and is a promising strategy to treat RA via combined anti-inflammatory mechanisms.

Self-assembly of amphiphilic phospholipid peptide dendrimer-based nanovectors for effective delivery of siRNA therapeutics in prostate cancer therapy

RNA interference (RNAi) holds great promise for therapeutic applications. However, safe and successful clinical translation essentially requires further advancement of developing efficient delivery systems. Herein, we report that amphiphilic phospholipid peptide dendrimers (AmPPDs) could mediated effective delivery of siRNA targeting Hsp27 for treating castration-resistant prostate cancer (CRPC). AmPPDs bears natural lipid derivative DSPE as the hydrophobic tail and different dendritic l-lysine as the hydrophilic head, capable of compacting siRNA into nanoparticles to protect it from enzymatic degradation. Interestingly, DSPE-KK2, AmPPD bearing smaller hydrophilic dendron, promoting more efficient intracellular uptake and endosome release of the so-formed siRNA complexes, as well as better siRNA releasing ability, ultimately resulting in more potent gene silencing and anticancer effects both in vitro and in vivo. Such outstanding performance of DSPE-KK2 in siRNA delivery may attribute to its optimal balance between the hydrophobic tail and hydrophilic dendritic portion. Our findings provide guidance for the development of safe and effective dendrimer-based siRNA delivery system, thus bringing new hope for combating various diseases.

Sequential delivery of dual drugs with nanostructured lipid carriers for improving synergistic tumor treatment effect

To improve synergistic anticancer efficacy and minimize the adverse effects of chemotherapeutic drugs, temozolomide (TMZ) and curcumin (CUR) co-loaded nanostructured lipid carriers (NLCs) were prepared by microemulsion in this study. And the physicochemical properties, drug release behavior, intracellular uptake efficiency, in vitro and in vivo anticancer effects of TMZ/CUR-NLCs were evaluated. TMZ/CUR-NLCs showed enhanced inhibitory effects on glioma cells compared to single drug loaded NLCs, which may be owing to that the quickly released CUR can sensitize the cancer cells to TMZ. The inhibitory mechanism is a combination of S phase cell cycle arrest associated with induced apoptosis. Notably, TMZ/CUR-NLCs can accumulate at brain and tumor sites effectively and perform a significant synergistic anticancer effect in vivo. More importantly, the toxic effects of TMZ/CUR-NLCs on major organs and normal cells at the same therapeutic dosage were not observed. In conclusion, NLCs are promising nanocarriers for delivering dual chemotherapeutic drugs sequentially, showing potentials in the synergistic treatment of tumors while reducing adverse effects both in vitro and in vivo.

Development of microRNA-21 mimic nanocarriers for the treatment of cutaneous wounds.

Rationale: Of the regulatory microRNAs expressed in the wounded skin, microRNA-21 (miR21) plays a pivotal role in wound repair by stimulating re-epithelialization, an essential feature to facilitate healing and reduce scar formation. Despite their crucial roles in wound healing, synthetic exogenous microRNAs have limited applications owing to the lack of an appropriate delivery system. Herein, we designed an miR21 mimic nanocarrier system using facial amphipathic bile acid-conjugated polyethyleneimines (BA-PEI) for the intracellular and transdermal delivery of synthetic miR21 molecules to accelerate wound repair.Methods: To design miR21 mimic nanocarriers, BA-conjugated PEIs prepared from three different types of BA at molar feed ratios of 1 and 3 were synthesized. The intracellular uptake efficiency of synthetic miR21 mimics was studied using confocal laser scanning microscopy and flow cytometry analysis. The optimized miR21/BA nanocarrier system was used to evaluate the wound healing effects induced by miR21 mimics in human HaCaT keratinocytes in vitro and a murine excisional acute wound model in vivo.Results: The cell uptake efficiency of miR21 complexed with BA-conjugated PEI was dramatically higher than that of miR21 complexed with PEI alone. Deoxycholic acid (DA)-modified PEI at a molar feed ratio of 3:1 (DA3-PEI) showed the highest transfection efficiency for miR21 without any increase in toxicity. After effective transdermal and intracellular delivery of miR21/DA3 nanocarriers, miR21 mimics promoted cell migration and proliferation through the post-transcriptional regulation of programmed cell death protein 4 (PDCD4) and matrix metalloproteinases. Thus, miR21 mimic nanocarriers improved both the rate and quality of wound healing, as evident from enhanced collagen synthesis and accelerated wound re-epithelialization.Conclusion: Our miRNA nanocarrier systems developed using DA3-PEI conjugates may be potentially useful for the delivery of synthetic exogenous miRNAs in various fields.

ROS-Mediated Apoptosis and Anticancer Effect Achieved by Artesunate and Auxiliary Fe(II) Released from Ferriferous Oxide-Containing Recombinant Apoferritin.

Reactive oxygen species (ROS)-mediated apoptosis is considered a crucial therapeutic mechanisms for artesunate (AS). As an Fe(II)-dependent drug, the anticancer effect of AS is often limited due to insufficient Fe(II) concentration in targeted cells. To overcome this problem, a recombinant apoferritin nanocarrier containing ferriferous oxide (M-HFn) is constructed to produce auxiliary exogenous Fe(II) when delivering AS to cancer cells. Here, the newly fabricated AS-loaded M-HFn nanoparticles (M-HFn@AS NPs) can significantly improve the tumor-specific targeting and intracellular uptake efficiency of AS in human cervical carcinoma cells. After being captured in the acidic cavity of endosomes, M-HFn@AS NPs can simultaneously release Fe(II) and allow AS to activate satisfactory ROS-mediated apoptosis. Furthermore, in vivo studies demonstrate that M-HFn@AS NPs can selectively accumulate in tumors to efficiently inhibit tumor growth. Thus, M-HFn@AS NPs are a promising system to enhance the therapeutic effect of Fe(II)-dependent drugs.

Cholesterol Anchors Enable Efficient Binding and Intracellular Uptake of DNA Nanostructures.

DNA nanostructures constitute a rapidly advancing tool-set for exploring cell-membrane functions and intracellular sensing or advancing delivery of biomolecularcargo into cells. Chemical conjugation with lipid anchors can mediate binding of DNA nanostructures to synthetic lipid bilayers, yet how such structures interact with biologicalmembranes and internalize cells has not been shown. Here, an archetypal 6-duplex nanobundle is used to investigate how lipid conjugation influences DNA cell binding and internalization kinetics. Cellular interactions of DNA nanobundles modified with one and three cholesterol anchors were assessed using flow cytometry and confocal microscopy. Nuclease digestion was used to distinguish surface-bound DNA, which is nuclease accessible, from internalized DNA. Three cholesterol anchors were found to enhance cellular association by up to 10-fold when compared with unmodified DNA. The bundles were endocytosed efficiently within 24 h. The results can help design controlled DNA binding and trafficking into cells.

Doxorubicin and Anti-PD-L1 Antibody Conjugated Gold Nanoparticles for Colorectal Cancer Photochemotherapy.

Colorectal cancer (CRC) is the third leading cause of cancer-related death worldwide.The prognosis and overall survival of CRCare known to be significantly correlated with the overexpression of PD-L1. Since combination therapies can significantly improve therapeutic efficacy, we constructed doxorubicin (DOX) conjugated and anti-PD-L1 targeting gold nanoparticles (PD-L1-AuNP-DOX) for the targeted chemo-photothermal therapy of CRC. DOX and anti-PD-L1 antibody were conjugated to the α-terminal end group of lipoic acid polyethylene glycol N-hydroxysuccinimide (LA-PEG-NHS) using an amide linkage, and PD-L1-AuNP-DOX was constructed by linking LA-PEG-DOX, LA-PEG-PD-L1, and a short PEG chain on the surface of AuNP using thiol-Au covalent bonds. Physicochemical characterizations and biological studies of PD-L1-AuNP-DOX were performed in the presence of near-infrared (NIR) irradiation (biologic studies were conducted using cellular uptake, apoptosis, and cell cycle assays in CT-26 cells). PD-L1-AuNP-DOX (40.0 ± 3.1 nm) was successfully constructed and facilitated the efficient intracellular uptake of DOX as evidenced by pronounced apoptotic effects (66.0%) in CT-26 cells. PD-L1-AuNP-DOX treatment plus NIR irradiation significantly and synergistically suppressed the in vitro proliferation of CT-26 cells by increasing apoptosis and cell cycle arrest. The study demonstrates that PD-L1-AuNP-DOX in combination with synergistic targeted chemo-photothermal therapy has a considerable potential for the treatment of localized CRC.

β‐Cyclodextrin‐Decorated Carbon Dots Serve as Nanocarriers for Targeted Drug Delivery and Controlled Release

AbstractA novel nanocarrier for targeted delivery of anti‐cancer drug doxorubicin (DOX) was fabricated with carbon dots (CDots) as the matrix. Fluorescent CDots capable of targeting folate receptor‐positive cells first conjugate with boric acid and then couple with β‐CD to produce the nanocarrier β‐CD/CDots. DOX was encapsulated into the cavity of β‐CD providing a maximum loading ratio of 27.3% at pH 7.4. Benefiting from pH‐sensitive dissociation of DOX/β‐CD inclusion complex and the cleavage of the bonding between boric acid and β‐CD, pH‐triggered release of drugs was realized, with an 82% release of the loaded drug at pH 5.0. Meanwhile, the fluorescence resonance energy transfer (FRET) occurs between CDots (donor) and DOX (acceptor), which may potentially facilitate monitoring/tracing of the drug delivery process. In vitro results further demonstrated the targeting capability of the nanocarrier towards folate receptor‐positive cells. Moreover, confocal microscopy results, in accordance with that of flow cytometry analysis, confirmed the efficient intracellular uptake of DOX‐β‐CD/CDots and sustained release of DOX. This makes DOX‐β‐CD/CDots promising as biocompatible and multifunctional nanomedicine for targeted delivery, controlled release and real time monitoring/tracing of drugs.

Layered double hydroxide nanostructures and nanocomposites for biomedical applications.

Layered double hydroxide (LDH) nanostructures and related nanocomposites have attracted significant interest in biomedical applications including cancer therapy, bioimaging and antibacterial treatment. These materials hold great advantages including low cost and facile preparation, convenient drug loading, high drug incorporation capacity, good biocompatibility, efficient intracellular uptake and endosome/lysosome escape, and natural biodegradability in an acidic environment. In this review, we summarize the development of three types of LDH nanostructures including pristine LDH, surface modified LDH, and LDH nanocomposites for a range of biomedical applications. The advantages and disadvantages of LDH nanostructures and insights into the future development are also discussed.