RESUMEN

Photochemotherapy has been recognized as a promising combinational modality for cancer treatment. However, difficulties such as off-target drug delivery, systemic toxicity, and the hypoxic nature of the tumor microenvironment remain hindrances to its application. To overcome these challenges, cancer cell membrane camouflaged perfluorooctyl bromide (PFOB) dual-layer nanopolymersomes bearing indocyanine green (ICG) and camptothecin (CPT), named MICFNS, were developed in this study, and melanoma was exploited as the model for MICFNS manufacture and therapeutic application. Our data showed that MICFNS were able to stabilize both ICG and CPT in the nanocarriers and can be quickly internalized by B16F10 cells due to melanoma membrane-mediated homology. Upon NIR irradiation, MICFNS can trigger hyperthermia and offer enhanced singlet oxygen production due to the incorporation of PFOB. With ≥10/2.5 µM ICG/CPT, MICFNS + NIR can provide comparable in vitro cancericidal effects to those caused by using an 8-fold higher dose of encapsulated CPT alone. Through the animal study, we further demonstrated that MICFNS can be quickly brought to tumors and have a longer retention time than those of free agents in vivo. Moreover, the MICFNS with 40/10 µM ICG/CPT in combination with 30 s NIR irradiation can successfully inhibit tumor growth without systemic toxicity in mice within the 14 day treatment. We speculate that such an antitumoral effect was achieved by phototherapy followed by chemotherapy, a two-stage tumoricidal process performed by MICFNS. Taken together, we anticipate that MICFNS, a photochemotherapeutic nanoplatform, has high potential for use in clinical anticancer treatment.

RESUMEN

Introduction: iRGD is usually used as a motif to modify siRNA-nanodelivery vectors to improve tumor-targeting and penetration. However, most of the modifications are realized by covalent conjugation, which normally requires complex preparation processes possibly with low conjugation efficiency and yield, and might lower its bioactivity. To avoid this, here, we presented an alternative physical method to decorate iRGD on nanopolymersomes via facile self-assembly in water. Methods: siVEGF was chosen as a siRNA model, and lipopolysaccharide-amine nanopolymersomes (NPs), an efficient cytosolic delivery vector developed by our group, was used as an original vector. By successively incubating siVEGF with NPs, followed by adding iRGD, a siVEGF-loaded NPs functionalized with iRGD (siRNA/iRGD-NPs) was obtained. The properties of iRGD-NPs or siRNA/iRGD-NPs were evaluated in vitro and in vivo. Results: iRGD is efficiently introduced onto NPs with different amounts, which can be precisely controlled by the feeding ratio. The introduced iRGD keeps tumor-targeting and -penetrating bioactivity, which endows iRGD-NPs with ~100% of tumor-cell uptake and excellent tumor spheroid-penetration, and thus iRGD-NPs can efficiently deliver siVEGF to significantly inhibit angiogenesis in zebrafish and tumor growth in nude mice bearing breast cancer without obvious toxicity. Conclusion: This study provides a facile physical method to decorate nanodelivery vectors with iRGD for effective targeted siRNA anti-tumor therapy.

Asunto(s)

RESUMEN

Smart polymer-based micro/nanoassemblies have emerged as a promising alternative for transporting and delivering a myriad of cargo. Cargo encapsulation into (or linked to) polymeric micro/nanocarrier (PC) strategies may help to conserve cargo activity and functionality when interacting with its surroundings in its journey to the target. PCs for cargo phototriggering allow for excellent spatiotemporal control via irradiation as an external stimulus, thus regulating the delivery kinetics of cargo and potentially increasing its therapeutic effect. Micromotors based on PCs offer an accelerated cargo-medium interaction for biomedical, environmental, and many other applications. This review collects the recent achievements in PC development based on nanomicelles, nanospheres, and nanopolymersomes, among others, with enhanced properties to increase cargo protection and cargo release efficiency triggered by ultraviolet (UV) and near-infrared (NIR) irradiation, including light-stimulated polymeric micromotors for propulsion, cargo transport, biosensing, and photo-thermal therapy. We emphasize the challenges of positioning PCs as drug delivery systems, as well as the outstanding opportunities of light-stimulated polymeric micromotors for practical applications.

RESUMEN

HYPOTHESIS: Osseointegration can be enhanced by introducing bioactive polyelectrolyte-multilayer films on implant surfaces. To guarantee films to function successfully in use, keeping structural integrity during implanting is necessary, which requires films with strong adhesion and cohesion to resist the mechanical damage. Catechol is considered as the origin of amazing adhesion of mussels. We hypothesize that catechol functionalization of polyelectrolytes enables film construction on implants in a non-aggressive way, and helps films resist mechanical damages during implanting. EXPERIMENTS: With lipopolysaccharide-amine nanopolymersomes (NPs), catechol-functionalized hyaluronic acid and NPs (cHA, cNPs) as a polycation, polyanion and primer, respectively, catechol-functionalized polyelectrolyte-multilayer films (cPEMs) were constructed on substrates via Layer-by-layer self-assembly. Effects of catechol functionalization on construction, surface properties, assembly mechanisms, structural integrity, mechanical properties and cytotoxicity of cPEMs were studied. FINDINGS: Self-adhesive cPEMs can be constructed on substrates, which grow exponentially and are driven by coordination, covalent bonding, electrostatic interactions, hydrogen bonding, etc. cPEMs with suitable catechol concentrations can resist mechanical damage to keep structural integrity in simulated clinical implantation, show stronger adhesion and cohesion than non-catechol-functionalized films in nanoscratch and nanoindentation tests, and are non-cytotoxic to MSCs. With excellent drug-loading and cytosolic-delivery capacity of NPs, cPEM is promising in improving osseointegration of implants.

Asunto(s)

RESUMEN

Purpose: Gene therapies via Noggin small interfering (si)RNA (siNoggin) and bone morphogenetic protein (BMP)-2 plasmid DNA (pBMP-2) may be promising strategies for bone repair/regeneration, but their ideal delivery vectors, efficacy difference, and underlying mechanisms have not been explored, so these issues were probed here. Methods: This study used lipopolysaccharide-amine nanopolymersomes (LNPs), an efficient cytosolic delivery vector developed by the research team, to mediate siNoggin and pBMP-2 to transfect MC3T3-E1 cells, respectively. The cytotoxicity, cell uptake, and gene knockdown efficiency of siNoggin-loaded LNPs (LNPs/siNoggin) were studied, then the osteogenic-differentiation efficacy of MC3T3-E1 cells treated by LNPs/pBMP-2 and LNPs/siNoggin, respectively, were compared by measuring the expression of osteogenesis-related genes and proteins, alkaline phosphatase (ALP) activity, and mineralization of the extracellular matrix at all osteogenic stages. Finally, the possible signaling pathways of the two treatments were explored. Results: LNPs delivered siNoggin into cells efficiently to silence 50% of Noggin expression without obvious cytotoxicity. LNPs/siNoggin and LNPs/pBMP-2 enhanced the osteogenic differentiation of MC3T3 E1 cells, but LNPs/siNoggin was better than LNPs/pBMP-2. BMP/Mothers against decapentaplegic homolog (Smad) and glycogen synthase kinase (GSK)-3ß/ß-catenin signaling pathways appeared to be involved in osteogenic differentiation induced by LNPs/siNoggin, but GSK-3ß/ß-catenin was not stimulated upon LNPs/pBMP-2 treatment. Conclusion: LNPs are safe and efficient delivery vectors for DNA and RNA, which may find wide applications in gene therapy. siNoggin treatment may be a more efficient strategy to enhance osteogenic differentiation than pBMP-2 treatment. LNPs loaded with siNoggin and/or pBMP-2 may provide new opportunities for the repair and regeneration of bone.

Asunto(s)

RESUMEN

Objective: To investigate the ability of gene-loaded lipopolysaccharide-amine nanopolymersomes (LNPs) in inducing osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) by in vitro gene transfection, where LNPs were used as a non-viral cationic carrier, and their properties were optimized during synthesis. Methods: LNPs were synthesized by a graft-copolymerization method, and the effects of different pH environments during synthesis on physicochemical properties of LNPs and LNPs/plasmid of bone morphogenetic protein 2-green fluorescent protein (pBMP-2-GFP) complexes were explored. Then, optimized LNPs with maximum transfection efficiency and safe cytotoxicity in rat BMSCs were identified by cytotoxicity and transfection experiments in vitro. Thereafter, the optimized LNPs were used to mediate pBMP-2-GFP to transfect rat BMSCs, and the influences of LNPs/pBMP-2-GFP on osteogenic differentiation of BMSCs were evaluated by monitoring the cell morphology, concentration of BMP-2 protein, activity of alkaline phosphatase (ALP), and the formation of calcium nodules. Results: The nitrogen content, particle size, and zeta potential of LNPs synthesized at pH 8.5 were lower than those of the other pH groups, with the lowest cytotoxicity (96.5%±1.4%) and the highest transfection efficiency (98.8%±0.1%). After transfection treatment, within the first 4 days, BMSCs treated by LNPs/pBMP-2-GFP expressed BMP-2 protein significantly higher than that treated by Lipofectamine2000 (Lipo)/pBMP-2-GFP, polyethylenimine 25K/pBMP-2-GFP, and the blank (non-treated). At 14 days after transfection, ALP activity in BMSCs treated by LNPs/pBMP-2-GFP was higher than that treated by Lipo/pBMP-2-GFP and the blank, comparable to that induced by osteogenic medium; with alizarin red staining, visible calcium nodules were found in BMSCs treated by LNPs/pBMP-2-GFP or osteogenic medium, but absent in BMSCs treated by Lipo/pBMP-2-GFP or the blank with apoptosis. At 21 days after transfection, transparent massive nodules were discovered in BMSCs treated by LNPs/pBMP-2-GFP, and BMSCs exhibited the morphologic features of osteoblasts. Conclusion: LNPs synthesized at pH 8.5 has optimal transfection efficiency and cytotoxicity, they can efficiently mediate pBMP-2-GFP to transfect BMSCs, and successfully induce their directional osteogenic differentiation, whose inducing effect is comparable to the osteogenic medium. The results suggest that gene transfection mediated by LNPs may be a convenient and effective strategy in inducing directional differentiation of stem cells.

Asunto(s)

RESUMEN

Tuberculosis (TB) has been stated as "the greatest killer worldwide due to a single infectious agent" behind the human immunodeficiency virus. Standard short-term treatment includes the oral administration of a combination of "first-line" drugs. However, poor-patient compliance and adherence to the long-term treatments represent one of the mayor drawbacks of the TB therapy. An alternative to the oral route is the pulmonary delivery of anti-TB drugs for local or systemic administration. Nanotechnology offers an attractive platform to develop novel inhalable/respirable nanocarriers. The present investigation was focused on the encapsulation of rifampicin (RIF) (a "first-line" anti-TB drug) within nanopolymersomes (nanoPS) employing di- and tri-block poly(ethylene glycol) (PEG)-poly(ɛ-caprolactone) (PCL) based copolymers as biomaterials. The derivatives presented a number-average molecular weight between 12.2 KDa and 30.1 KDa and a hydrophobic/hydrophilic balance between 0.56 and 0.99. The nanoPS were able to enhance the apparent RIF aqueous solubility (up to 4.62 mg/mL) where the hydrodynamic diameters of the drug-loaded systems (1% w/v) were ranged between 65.8 nm and 94 nm at day 0 as determined by dynamic light scattering (DLS). Then, RIF-loaded systems demonstrated as excellent colloidal stability in aqueous media over 14 days with a spherical morphology as determined by transmission electron microscopy (TEM). Furthermore, RIF-loaded nano-sized PS promoted drug accumulation in macrophages (RAW 264.7) versus a drug solution representing promising results for a potential TB inhaled therapy.

Asunto(s)

RESUMEN

Successful in vivo gene delivery mediated by nonviral vectors requires efficient extracellular and intracellular gene delivery, but few studies have given attention to the former. That is why numerous gene delivery systems have succeeded in vitro, while the expected clinical success has not come about. To realize efficient extracellular gene delivery, the stability of vectors and/or their complexes with genes in body fluids is first required, which prevents loaded genes from premature unloading and degradation. Furthermore, the storage stability of vectors under common conditions is important for their widespread applications. Lipopolysaccharide-amine nanopolymersomes (NPs), a gene vector developed by our group recently, have higher than 95% in vitro transfection efficiency in mesenchymal stem cells when delivering pEGFP, and induce significant angiogenesis in zebrafish when delivering plasmid encoding vascular endothelial growth factor deoxyribonucleic acid (pVEGF). To reveal their extracellular delivery ability and storage stability, in this study their stability in various simulant physiological environments and storage conditions was systematically studied by monitoring their changes in disassembly, size, zeta potential, and transfection efficiency. Additionally, damage to the mitochondria of mesenchymal stem cells was evaluated. Results show that NPs and plasmid deoxyribonucleic acid (pDNA)-loaded NPs (pNPs) have acceptable stability against dilution, anions, salts, pH, enzyme, and serum, presumably assuring their efficient extracellular delivery in vivo. Moreover, both the lyophilized NPs at room temperature and NP/pNP solution at 4°C have high storage stability, and pNPs show low damage to the mitochondria. The acceptable stability of NPs combined with compatibility and efficient gene transfection highlight their huge potential in the clinic as a gene delivery vector.

Asunto(s)

RESUMEN

Targeted delivery of anti-cancer agents exclusively to tumor cells introduces an attractive strategy because it increases the therapeutic index compared with untargeted drugs. Aptamer conjugated nanoparticles that can specifically bind to the proteins on a tumor cell surface are capable nanoscale delivery systems for enhancing cellular uptake of chemotherapeutic agents. The epithelial cell adhesion molecule (EpCAM) as a cancer stem cell marker emerges as a versatile target for aptamer-based cancer therapy due to its high expression level in various adenocarcinoma cell lines and its very low expression level in normal cells. We developed EpCAM-targeted PEG-PLGA nanopolymersomes by covalently coupling the EpCAM aptamer to the surface of nanopolymersomes loaded with the anticancer agent doxorubicin via pH gradient method. The results indicated that doxorubicin was entrapped in PEG-PLGA nanopolymersomes with encapsulation efficiency and loading content of 91.25±4.27% and 7.3±0.34%, respectively. Over a period of 5 days, up to 8% of the DOX was released through this system. The doxorubicin-loaded aptamer conjugated nanopolymersomes exhibited efficient cell uptake and internalization, and were significantly more cytotoxic (P<0.01) toward EpCAM-positive tumor cells (MCF-7) than non-targeted nanopolymersomes. Our data suggest that EpCAM-targeted nanopolymersomes will lead to an improved therapeutic index of doxorubicin to EpCAM positive cancer cells.

Asunto(s)

RESUMEN

To explore a spatiotemporally controllable gene delivery system with high efficiency and safety, polyelectrolyte multilayer (PEM) films were constructed on titanium or quartz substrates via layer-by-layer self-assembly technique by using plasmid deoxyribonucleic acid-loaded lipopolysaccharide-amine nanopolymersomes (pNPs) as polycations and hyaluronic acid (HA) as polyanions. pNPs were chosen because they have high transfection efficiency (>95%) in mesenchymal stem cells (MSCs) and induce significant angiogenesis in zebrafish in conventional bolus transfection. The assembly process of PEM films was confirmed by analyses of quartz crystal microbalance with dissipation, X-ray photoelectron spectroscopy, infrared, contact angle, and zeta potential along with atomic force microscopy observation. Quartz crystal microbalance with dissipation analysis reveals that this film grows in an exponential mode, pNPs are the main contributor to the film mass, and the film mass can be modulated in a relatively wide range (1.0-29 µg/cm(2)) by adjusting the deposition layer number. Atomic force microscopy observation shows that the assembly leads to the formation of a patterned film with three-dimensional tree-like nanostructure, where the branches are composed of beaded chains (pNP beads are strung on HA molecular chains), and the incorporated pNPs keep structure intact. In vitro release experiment shows that plasmid deoxyribonucleic acid can be gradually released from films over 14 days, and the released plasmid deoxyribonucleic acid exists in a complex form. In vitro cell experiments demonstrate that PEM films can enhance the adhesion and proliferation of MSCs and efficiently transfect MSCs in situ in vitro for at least 4 days. Our results suggest that a (pNPs/HA)n system can mediate efficient transfection in stem cells in a spatially and temporally controllable pattern, highlighting its huge potential in local gene therapy.

Asunto(s)