Multifunctional Nanovectors Research Articles

Nanoscale Surface-Enhanced Raman Spectroscopy Investigation of a Polyphenol-Based Plasmonic Nanovector.

The demand for next-generation multifunctional nanovectors, combining therapeutic effects with specific cellular targeting, has significantly grown during the last few years, pursuing less invasive therapy strategies. Polyphenol-conjugated silver nanoparticles (AgNPs) appear as potential multifunctional nanovectors, integrating the biorecognition capability and the antioxidant power of polyphenols, the antimicrobial activity of silver, and the drug delivery capability of NPs. We present a spectroscopic and microscopic investigation on polyphenol-synthesized AgNPs, selecting caffeic acid (CA) and catechol (CT) as model polyphenols and using them as reducing agents for the AgNP green synthesis, both in the presence and in the absence of a capping agent. We exploit the plasmonic properties of AgNPs to collect Surface-Enhanced Raman Scattering (SERS) spectra from the nanosized region next to the Ag surface and to characterize the molecular environment in the proximity of the NP, assessing the orientation and tunable deprotonation level of CA, depending on the synthesis conditions. Our results suggest that the SERS investigation of such nanovectors can provide crucial information for their perspective biomedical application.

Biological activity of gold nanoparticles combined with the NFL-TBS.40-63 peptide, or with other cell penetrating peptides, on rat glioblastoma cells

Targeting, detecting, and destroying selectively cancer cells or specific organelles is a major challenge of nanomedicine. Recently, a new methodology was conceived to synthesize gold nanoparticles combined with a peptide having a C-terminal biotin (BIOT-NFL-peptide). This methodology called “Method IN” allows specific interactions between the BIOT-NFL-peptide, the polyethylene glycol diacid (PEG-COOH) and the gold salt (Au III) to produce multifunctional hybrid nano-carriers called BIOT-NFL-PEG-AuNPs. Here, we show that it is possible to use this strategy to synthesize multifunctional hybrid nano-carriers with other cell-penetrating peptides including TAT and Vim-peptides. Ex-vivo studies on F98 rat glioblastoma cells show that these new nanovectors acquire the cellular entry function of peptides and the gold particles make it possible to visualize by electron microscopy their localization in organelles. Thus, these new multifunctional nanovectors offer promising possibilities for the theranostic field, including the cell-penetrating property of the peptide, the intra-organelle localization of gold particles and their possible thermoplasmonic properties, as well as the stealth property of PEG.

Abstract 367: Nano-immunotherapy in TNBC: Aptamer-based nanoparticles for PD-L1 siRNA delivery to cancer cells

Abstract Triple-negative breast cancer (TNBC) is a heterogeneous and aggressive group of breast cancers. The lack of specific actionable targets makes chemotherapy the main treatment for TNBC patients. However, chemotherapy has limited success due to scarce bioavailability, severe systemic side effects and drug resistance. Polymeric nanoparticles (PNPs) may efficiently deliver in vivo therapeutics to tumors when conjugated to specific targeting agents. Potential agents for targeting tumor cells are aptamers: short, single-stranded oligonucleotides that interact at high affinity with their targets. Here, we report the characterization of new multifunctional nanovectors consisting of safe and biodegradable PNPs, highly specific TNBC aptamers as delivery agents and artificial small interfering RNA (siRNA) as drug payload, designed to suppress programmed cell death-ligand 1 (PD-L1) expression, a major feature of immune evasion in cancer cells. We efficiently entrapped siRNA-PD-L1 into PNPs. To enable active targeting, siPD-L1-PNPs were functionalized with TN145-aptamer, which we previously generated by cell-SELEX and shown to bind with nanomolar affinity to TNBC cells distinguishing them from both normal breast cells and non-TNBC breast cancer cells. TN145 aptamer actively internalizes into target cells, thus representing a good candidate to deliver a therapeutic payload. We show that the aptamer-decorated nanovectors efficiently deliver fluorescein-labeled siRNA into TNBC MDA-MB-231 and BT-549 cells, as assessed by confocal microscopy. Unconjugated nanovectors or conjugated with scrambled aptamers were used as controls. Non-TNBC BT-474 and MCF7 breast cancer cells, were used to exclude unspecific binding. Importantly, a 30-min incubation of TN145-conjugated nanovectors on target cells, at a siPD-L1 concentration of 1 nM, results in stronger PD-L1 silencing than that achieved by siPD-L1 delivered via a commercial transfection reagent. Furthermore, TN145-PNPs loaded with both siPD-L1 and cisplatin were generated and the efficacy of combined treatment was tested on tumor cells and tumor and immune cell co-cultures. Chemotherapy, including cisplatin, has been reported to induce PD-L1 enrichment in TNBC cells, hence an aptamer-targeted nanosystem enabling the synergistic effect of siRNA that directly knocks down PD-L1 expression on tumor cells with a powerful chemotherapeutic drug could be the future way to eradicate TNBC cells. Citation Format: Lisa Agnello, Simona Camorani, Silvia Tortorella, Annachiara d’Argenio, Roberto Nilo, Monica Fedele, Antonella Zannetti, Mauro Comes Franchini, Laura Cerchia. Nano-immunotherapy in TNBC: Aptamer-based nanoparticles for PD-L1 siRNA delivery to cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 367.

Lanthanide-based β-Tricalcium Phosphate Upconversion Nanoparticles as an Effective Theranostic Nonviral Vectors for Image-Guided Gene Therapy.

Lanthanide-based beta-tricalcium phosphate (β-TCP) upconversion nanoparticles are exploited as a non-viral vector for imaging guided-gene therapy by virtue of their unique optical properties and multi-modality imaging ability, high transfection efficiency, high biocompatibility, dispersibility, simplicity of synthesis and surface modification. Ytterbium and thulium-doped β-TCP nanoparticles (βTCPYbTm) are synthesized via co-precipitation method, coated with polyethylenimine (PEI) and functionalized with a nuclear-targeting peptide (TAT). Further, in vitro studies revealed that the nanotheranostic carriers are able to transfect cells with the plasmid eGFP at a high efficiency, with approximately 60% of total cells producing the fluorescent green protein. The optimized protocol developed comprises the most efficient βTCPYbTm/PEI configuration, the amount and the order of assembly of βTCPYbTm:PEI, TAT, plasmid DNA and the culturing conditions. With having excellent dispersibility and high chemical affinity toward nucleic acid, calcium ions released from βTCPYbTm:PEI nanoparticles can participate in delivering nucleic acids and other therapeutic molecules, overcoming the nuclear barriers and improving the transfection efficacy. Equally important, the feasibility of the upconversion multifunctional nanovector to serve as an effective contrast agent for imaging modality, capable of converting low-energy light to higher-energy photons via a multi-photons mechanism, endowing greater unique luminescent properties, was successfully demonstrated.

Step-by-Step Design of New Theranostic Nanoformulations: Multifunctional Nanovectors for Radio-Chemo-Hyperthermic Therapy under Physical Targeting

While investigating the possible synergistic effect of the conventional anticancer therapies, which, taken individually, are often ineffective against critical tumors, such as central nervous system (CNS) ones, the design of a theranostic nanovector able to carry and deliver chemotherapy drugs and magnetic hyperthermic agents to the target radiosensitizers (oxygen) was pursued. Alongside the original formulation of polymeric biodegradable oxygen-loaded nanostructures, their properties were fine-tuned to optimize their ability to conjugate therapeutic doses of drugs (doxorubicin) or antitumoral natural substances (curcumin). Oxygen-loaded nanostructures (diameter = 251 ± 13 nm, ζ potential = −29 ± 5 mV) were finally decorated with superparamagnetic iron oxide nanoparticles (SPIONs, diameter = 18 ± 3 nm, ζ potential = 14 ± 4 mV), producing stable, effective and non-agglomerating magnetic nanovectors (diameter = 279 ± 17 nm, ζ potential = −18 ± 7 mV), which could potentially target the tumoral tissues under magnetic driving and are monitorable either by US or MRI imaging.

Urinary exosomes-based Engineered Nanovectors for Homologously Targeted Chemo-Chemodynamic Prostate Cancer Therapy via abrogating EGFR/AKT/NF-kB/IkB signaling

Multi-functional nanovectors based on exosomes from cancer cell culture supernatants in vitro has been successfully utilized for tumor-specific targeting and immune escape. However, the labor-intensive purification procedures for rich-dose and high-purity homogeneous exosomes without using targeting ligands are still a challenging task. Herein, we developed a nanovector Exo-PMA/Fe-HSA@DOX through cloaked by urinary exosome membrane as a chemo/chemodynamic theranostic nano-platform for targeted homologous prostate cancer therapy which pertain to the abrogation of Epidermal Growth Factor Receptor (EGFR) and its downstream AKT/NF-kB/IkB signaling instead of ERK signaling cascades. Urinary exosomes-based nanovectors own the same urological cancer cell membrane antigen inclusive of E-cadherin, CD 47 and are free from intracellular substance such as Histone 3 and COX Ⅳ. The targeting properties of the homologous cancer cell are well preserved in Exo-PMA/Fe-HSA@DOX nanovectors in high purity. Meanwhile, the nanovectors based on urinary exosomes from prostate patients deeply penetrated into prostate cancer DU145 3D MCTS, and successfully achieve superior synergistic low-dose chemo/chemodynamic performance in vivo. In addition, the blockage of bypassing EGFR/AKT/NF-kB/IkB signaling pathway is greatly enhanced via elevated intracellular PMA/Fe-HSA@DOX nanoparticles (NPs). It is expected that the rich source and high purity of urinary exosomes offer a reliable solution for mass production of such nanovectors in the future. The targeted homologous cancer therapy based on the urinary exosomes from cancer patients exemplifies a novel targeted anticancer scheme with efficient and facile method.

Synthesis of Multi-Functional Nano-Vectors for Target-Specific Drug Delivery.

Magnetic nanoparticles have gained attention in cancer therapy due to their non-toxic properties and high bio-compatibility. In this report, we synthesize a dual-responsive magnetic nanoparticle (MNP) that is sensitive to subtle pH and temperature change as in the tumor microenvironment. Thus, the functional doxorubicin (DOX)-loaded MNP (DOX-PNIPAM-PMAA@Fe3O4) can perform specific DOX releases in the cancer cell. The particle was characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS), zeta-potential, Fourier-transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The microscopy data revealed the particle as having a spherical shape. The zeta-potential and size distribution analysis data demonstrated the difference for the stepwise modified MNPs. The FTIR spectrum showed characteristic absorption bands of NH2-SiO2@Fe3O4, CPDB@Fe3O4, PMAA@Fe3O4, and PNIPAM-PMAA@Fe3O4. Drug-loading capacity and releasing efficiency were evaluated under different conditions. Through an in vitro analysis, we confirmed that PNIPAM-PMAA@Fe3O4 has enhanced drug releasing efficiency under acidic and warmer conditions. Finally, cellular uptake and cell viability were estimated via different treatments in an MDA-MB-231 cell line. Through the above analysis, we concluded that the DOX-loaded particles can be internalized by cancer cells, and such a result is positive and prospective.

Multifunctional Silica-Based Nanoparticles with Controlled Release of Organotin Metallodrug for Targeted Theranosis of Breast Cancer.

Three different multifunctional nanosystems based on the tethering onto mesoporous silica nanoparticles (MSN) of different fragments such as an organotin-based cytotoxic compound Ph3Sn{SCH2CH2CH2Si(OMe)3} (MSN-AP-Sn), a folate fragment (MSN-AP-FA-Sn), and an enzyme-responsive peptide able to release the metallodrug only inside cancer cells (MSN-AP-FA-PEP-S-Sn), have been synthesized and fully characterized by applying physico-chemical techniques. After that, an in vitro deep determination of the therapeutic potential of the achieved multifunctional nanovectors was carried out. The results showed a high cytotoxic potential of the MSN-AP-FA-PEP-S-Sn material against triple negative breast cancer cell line (MDA-MB-231). Moreover, a dose-dependent metallodrug-related inhibitory effect on the migration mechanism of MDA-MB-231 tumor cells was shown. Subsequently, the organotin-functionalized nanosystems have been further modified with the NIR imaging agent Alexa Fluor 647 to give three different theranostic silica-based nanoplatforms, namely, MSN-AP-Sn-AX (AX-1), MSN-AP-FA-Sn-AX (AX-2), and MSN-AP-FA-PEP-S-Sn-AX (AX-3). Their in vivo potential as theranostic markers was further evaluated in a xenograft mouse model of human breast adenocarcinoma. Owing to the combination of the receptor-mediated site targeting and the specific fine-tuned release mechanism of the organotin metallodrug, the nanotheranostic drug MSN-AP-FA-PEP-S-Sn-AX (AX-3) has shown targeted diagnostic ability in combination with enhanced therapeutic activity by promoting the inhibition of tumor growth with reduced hepatic and renal toxicity upon the repeated administration of the multifunctional nanodrug.

The Synergy between CRISPR and Chemical Engineering.

Gene therapy and transgenic research have advanced quickly in recent years due to the development of CRISPR technology. The rapid development of CRISPR technology has been largely benefited by chemical engineering. Firstly, chemical or synthetic substance enables spatiotemporal and conditional control of Cas9 or dCas9 activities. It prevents the leaky expression of CRISPR components, as well as minimizes toxicity and off-target effects. Multi-input logic operations and complex genetic circuits can also be implemented via multiplexed and orthogonal regulation of target genes. Secondly, rational chemical modifications to the sgRNA enhance gene editing efficiency and specificity by improving sgRNA stability and binding affinity to on-target genomic loci, and hence reducing off-target mismatches and systemic immunogenicity. Chemically-modified Cas9 mRNA is also more active and less immunogenic than the native mRNA. Thirdly, nonviral vehicles can circumvent the challenges associated with viral packaging and production through the delivery of Cas9-sgRNA ribonucleoprotein complex or large Cas9 expression plasmids. Multi-functional nanovectors enhance genome editing in vivo by overcoming multiple physiological barriers, enabling ligand-targeted cellular uptake, and blood-brain barrier crossing. Chemical engineering can also facilitate viral-based delivery by improving vector internalization, allowing tissue-specific transgene expression, and preventing inactivation of the viral vectors in vivo. This review aims to discuss how chemical engineering has helped improve existing CRISPR applications and enable new technologies for biomedical research. The usefulness, advantages, and molecular action for each chemical engineering approach are also highlighted.

Transformation of Viral Light Particles into Near-Infrared Fluorescence Quantum Dot-Labeled Active Tumor-Targeting Nanovectors for Drug Delivery.

Nanosized oncolytic viral light particles (L-particles), separated from progeny virions, are composed of envelopes and several tegument proteins of viruses, free of nucleocapsids. The noninfectious L-particles experience the same internalization process as mature oncolytic virions, which exhibits great potential to act as targeted therapeutic platforms. However, the clinical applications of L-particle-based theranostic platforms are rare due to the lack of effective methods to transform L-particles into nanovectors. Herein, a convenient and mild strategy has been developed to transform L-particles into near-infrared (NIR) fluorescence Ag2Se quantum dot (QD)-labeled active tumor-targeting nanovectors for real-time in situ imaging and drug delivery. Utilizing the electroporation technique, L-particles can be labeled with ultrasmall water-dispersible NIR fluorescence Ag2Se QDs with a labeling efficiency of ca. 85% and loaded with antitumor drug with a loading efficiency of ca. 87%. Meanwhile, by harnessing the infection mechanism of viruses, viral L-particles are able to recognize and enter tumor cells without further modification. In sum, a trackable and actively tumor-targeted theranostics nanovector can be obtained efficiently and simultaneously. Such multifunctional nanovectors transformed from viral L-particles have exhibited excellent properties of active tumor-targeting, in vivo tumor imaging, and antitumor efficacy, which opens a new window for the development of natural therapeutic nanoplatforms.

Multifunctional Nanovectors Based on Polyamidoamine Polymers for Theranostic Application.

We present multifunctional, biocompatible and biodegradable magnetic nanovectors based on different polyamidoamine (PAA) polymers tailored with different diagnostic and therapeutic properties. Using maghemite nanoparticles with average size 15.5 ± 2.8 nm prepared by thermal decomposition, superparamagnetic nanovectors were obtained by coating the nanoparticles with synthetic polymers of PAA. These have a segmented copolymer structure, and bear PAA segments containing different amount of carboxyl groups per repeating units together with PEG segments. These copolymers are thought to combine the binding properties of the carboxylated PAA segments to inorganic nanoparticles, with the stealth properties of the PEG ones. The magnetic, hyperthermal and relaxometric properties of the synthesized samples were investigated. Magnetic measurements revealed that the samples are superparamagnetic at room temperature and the overall magnetic behavior is not affected by the functionalization process. Calorimetric measurements demonstrated a good heating efficiency at alternating magnetic field parameters below the human tolerability threshold (SAR of ca. 70 W/g at 260 Hz and 10.8 kA/m). 1H-NMR relaxivities were relevant compared to the values of the commercial contrast agents over the whole investigated frequency range.

Self-assembling Nanotechnology for Cancer Personalized Medicine

domenico.marson@dia.units.itTheranostics is a new field of medicine, which combines specific targeted therapies and diagnostic tests. With a key focus on patient centered care, theranostics provides a transition from conventional medicine to a contemporary personalized and precision medicine approach. The theranostic paradigm in cancer involves nanoscience to unite diagnostic and therapeutic applications to form nanosized agents for diagnosis, drug/gene delivery and treatment response monitoring. These nanocarriers can indeed be engineered to precisely control drug/gene/sensor-release rate and/or target specific organs/tissues within the body with a specific amount of therapeutic/diagnostic agent. In order to fulfill these expectations, any nanovector system must be designed to transport the optimum amount of therapeutic/diagnostic cargo to the desired target site where the active principle is to be released at an optimal rate during a specific time window.Keeping the promises of theranostics is a current formidable challenge in (bio)nanotechnology, and major efforts are devoted to the design of integrated multifunctional and multivalent nanovectors able to provide selective recognition combined with sustained release and/or diagnostic reporting. In this contribution, the pathway leading to two types of nanosystems obtained by exploiting the quintessence of nanotechnology, i.e., the self-assembling process of small, amphiphilic molecules, is reported. Depending on the specific chemistry adopted, these nanomicelles are able to perform specific and effective gene silencing via targeted small interfering RNA (siRNA) delivery, and provide PET images with significantly superior imaging quality relating to sensitivity, specificity and accuracy when compared to the clinical standard [18F]FDG.

Imaging modification of colon carcinoma cells exposed to lipid based nanovectors for drug delivery: a scanning electron microscopy investigation.

The adsorption at cell surfaces and cell internalization of two drug delivery lipid based nanovectors has been investigated by means of Field Emission Scanning Electron Microscopy (FE-SEM) operating at low beam voltage on two different colon carcinoma cell lines, CaCo-2 and CoLo-205, that were compared with the M14 melanoma cell line, as a reference. The cells were incubated with the investigated multifunctional nanovectors, based on liposomes and magnetic micelles loaded with 5-fluorouracil, as a chemotherapeutic agent, and a FE-SEM systematic investigation was performed, enabling a detailed imaging of any morphological changes of the drug exposed cells as a function of time. The results of the FE-SEM investigation were validated by MTS assay and immunofluorescence staining of the Ki-67 protein performed on the investigated cell lines at different times. The two nanoformulations resulted in a comparable effect on CaCo-2 and M14 cell lines, while for CoLo 205 cells, the liposomes provided an cytotoxic activity higher than that observed in the case of the micelles. The study highlighted the high potential of FE-SEM as a valuable complementary technique for imaging and monitoring in time the drug effects on the selected cells exposed to the two different nanoformulations.

Multifunctional temozolomide-loaded lipid superparamagnetic nanovectors: dual targeting and disintegration of glioblastoma spheroids by synergic chemotherapy and hyperthermia treatment.

Aiming at finding new solutions for fighting glioblastoma multiforme, one of the most aggressive and lethal human cancer, here an in vitro validation of multifunctional nanovectors for drug delivery and hyperthermia therapy is proposed. Hybrid magnetic lipid nanoparticles have been fully characterized and tested on a multi-cellular complex model resembling the tumor microenvironment. Investigations of cancer therapy based on a physical approach (namely hyperthermia) and on a pharmaceutical approach (by exploiting the chemotherapeutic drug temozolomide) have been extensively carried out, by evaluating its antiproliferative and pro-apoptotic effects on 3D models of glioblastoma multiforme. A systematic study of transcytosis and endocytosis mechanisms has been moreover performed with multiple complimentary investigations, besides a detailed description of local temperature increments following hyperthermia application. Finally, an in-depth proteomic analysis corroborated the obtained findings, which can be summarized in the preparation of a versatile, multifunctional, and effective nanoplatform able to overcome the blood-brain barrier and to induce powerful anti-cancer effects on in vitro complex models.

Designed inorganic porous nanovector with controlled release and MRI features for safe administration of doxorubicin

The inability of traditional chemotherapeutics to reach cancer tissue reduces the treatment efficacy and leads to adverse effects. A multifunctional nanovector was developed consisting of porous silicon, superparamagnetic iron oxide, calcium carbonate, doxorubicin and polyethylene glycol. The particles integrate magnetic properties with the capacity to retain drug molecules inside the pore matrix at neutral pH to facilitate drug delivery to tumor tissues. The MRI applicability and pH controlled drug release were examined in vitro together with in-depth material characterization. The in vivo biodistribution and compound safety were verified using A549 lung cancer bearing mice before proceeding to therapeutic experiments using CT26 cancer implanted mice. Loading doxorubicin into the porous nanoparticle negated the adverse side effects encountered after intravenous administration highlighting the particles’ excellent biocompatibility. Furthermore, the multifunctional nanovector induced 77% tumor reduction after intratumoral injection. The anti-tumor effect was comparable with that of free doxorubicin but with significantly alleviated unwanted effects. These results demonstrate that the developed porous silicon-based nanoparticles represent promising multifunctional drug delivery vectors for cancer monitoring and therapy.

Reversal of tumor malignization and modulation of cell behaviors through genome editing mediated by a multi-functional nanovector.

To effectively reverse tumor malignization by genome editing, a multi-functional self-assembled nanovector for the delivery of a genome editing plasmid specifically to tumor cells was developed. The nanovector core consisting of protamine and calcium carbonate entrapping the CRISPR-Cas9 plasmid is decorated by aptamer incorporated heparin. Owing to a high affinity between a MUC1 specific aptamer and mucin 1 (MUC1) overexpressed in tumor cells as well as the interaction between AS1411 and nucleolin on the tumor cell surface and cell nuclei, the nanovector can target the nuclei of tumorous cells for the knockout of focal adhesion kinase (FAK). Notably, the genome editing mediated by our delivery systems can effectively modulate cell behaviors and thus reverse tumor malignization. Up-regulated p53, p16, p21, E-cadherin, CD80, MICA, MICB and Fas, together with down-regulated MMP-9, vimentin, VEGF, TGF-β, CD47 and CD133 in genome edited cells indicate that the genome editing system can inhibit cancerous cell growth, prevent tumor invasion and metastasis, reverse tumor-induced immune suppression, and inhibit cancer stemness. More importantly, the edited cells can maintain the modulated cellular function after succeeding subcultures.

In Situ Reductive Synthesis of Structural Supported Gold Nanorods in Porous Silicon Particles for Multifunctional Nanovectors.

Porous silicon nanodisks (PSD) were fabricated by the combination of photolithography and electrochemical etching of silicon. By using PSD as a reducing agent, gold nanorods (AuNR) were in situ synthesized in the nanopores of PSD, forming PSD-supported-AuNR (PSD/AuNR) hybrid particles. The formation mechanism of AuNR in porous silicon (pSi) was revealed by exploring the role of pSi reducibility and each chemical in the reaction. With the PSD support, AuNR exhibited a stable morphology without toxic surface ligands (CTAB). The PSD/AuNR hybrid particles showed enhanced plasmonic property compared to free AuNR. Because high-density "hot spots" can be generated by controlling the distribution of AuNR supported in PSD, surface-enhanced raman scattering (SERS) using PSD/AuNR as particle substrates was demonstrated. A multifunctional vector, PSD/AuNR/DOX, composed of doxorubicin (DOX)-loaded PSD/AuNR capped with agarose (agar), was developed for highly efficient, combinatorial cancer treatment. Their therapeutic efficacy was examined using two pancreatic cancer cell lines, PANC-1 and MIA PaCa-2. PSD/AuNR/DOX (20 μg Au and 1.25 μg DOX/mL) effectively destroyed these cells under near-IR laser irradiation (810 nm, 15 J·cm(-2) power, 90 s). Overall, we envision that PSD/AuNR may be a promising injectable, multifunctional nanovector for biomedical application.

Multi-ligand functionalized particle design for cell targeting and drug delivery

Particle-based delivery systems encompass some of the most promising techniques for therapeutic drug delivery. In particular, multi-functional nanovector systems permit diverse functions such as efficient drug/imaging agent loading and unloading and increased target specificity. To enhance the efficiency of delivery systems, particle size and shape can be altered and specific ligands can be conjugated to the particles to promote interactions with receptors expressed on target cells. Moreover, to maximize efficiency and specificity, multiple types of ligands can be conjugated to the particle surface. To analyze the multi-ligand-receptor mediated adhesion process, we developed a stochastic model considering diverse biophysical parameters, including non-specific interactions, ligand-receptor specific interactions, kinetic affinity between ligand and receptor, hydrodynamic force and particle size. The results demonstrate that limited contact area restricts the probability of adhesion such that multiple ligand-receptor pairs do not always show enhanced adhesion characteristics. To optimize the effect of multiple ligand-receptor pairs, biophysical parameters must be considered.

80 - Metal implanted multi-functional nanovectors for targeted radiotherapy and diagnostics of cancer

80 - Metal implanted multi-functional nanovectors for targeted radiotherapy and diagnostics of cancer

Real-time fluorescence tracking of gene delivery via multifunctional nanocomposites.

Fluorescence imaging of transduced cells and tissues is valuable in the development of gene vectors and the evaluation of gene therapy efficacy. We report here the simple and rational design of multifunctional nanocomposites (NCs) for simultaneous gene delivery and fluorescence tracking based on ZnS:Mn(2+) quantum dots (QDs) and positively charged polymer coating. The positively charged imidazole in the as-synthesized amphiphilic copolymer can be used for gene loading via electrostatic interaction. While the introduced poly(ethylene glycol) (PEG) can be used to reduce the binding of plasma proteins to nanovectors and minimize clearance by the reticuloendothelial system after intravenous administration. Most importantly, these multifunctional nanovectors showed much lower cellular toxicity than the commercial polyethylenimine (PEI) transfection vectors. On the basis of the red fluorescence of QDs, we can real-time track the gene delivery in cells, and the transfection efficacy of pDNA encoding enhanced green fluorescence protein (pEGFP) was monitored via the green fluorescence of the GFP expressed by the pDNA delivered into the nuclei. Fluorescence imaging analysis confirmed that the QDs-based nanovectors delivered pDNA into HepG2 cells efficiently. These new insights and capabilities pave a new way toward nanocomposite engineering for fluorescence imaging tracking of gene therapy.