Tianyi Kang

3D-engineering of Cellularized Conduits for Peripheral Nerve Regeneration.

Tissue engineered conduits have great promise for bridging peripheral nerve defects by providing physical guiding and biological cues. A flexible method for integrating support cells into a conduit with desired architectures is wanted. Here, a 3D-printing technology is adopted to prepare a bio-conduit with designer structures for peripheral nerve regeneration. This bio-conduit is consisted of a cryopolymerized gelatin methacryloyl (cryoGelMA) gel cellularized with adipose-derived stem cells (ASCs). By modeling using 3D-printed “lock and key” moulds, the cryoGelMA gel is structured into conduits with different geometries, such as the designed multichannel or bifurcating and the personalized structures. The cryoGelMA conduit is degradable and could be completely degraded in 2-4 months in vivo. The cryoGelMA scaffold supports the attachment, proliferation and survival of the seeded ASCs, and up-regulates the expression of their neurotrophic factors mRNA in vitro. After implanted in a rat model, the bio-conduit is capable of supporting the re-innervation across a 10 mm sciatic nerve gap, with results close to that of the autografts in terms of functional and histological assessments. The study describes an indirect 3D-printing technology for fabricating cellularized designer conduits for peripheral nerve regeneration, and could lead to the development of future nerve bio-conduits for clinical use.

Efficient delivery of antigen to DCs using yeast-derived microparticles

Some pathogens can be naturally recognized and internalized by antigen presentation cells (APCs) in vivo, providing a platform for efficient vaccine delivery. However, the biosafety concerns discourage the clinical applications of live pathogens. Here, yeast-derived microparticles were prepared for cancer vaccine delivery. By chemical treatment of bread yeast, capsular yeast shell (YS) microparticles were obtained. Ovalbumin (OVA), as a model antigen, was conjugated to the surface of YS. Results indicated that these YS microparticles with a uniform size of ~3.4 μm can be recognized and internalized by dendritic cells (DCs). The YS-mediated antigen delivery can enhance the cellular uptake of antigen by DCs, promote the maturation of DCs, and trigger DCs to release immune co-stimulatory molecules. Immunization with YS-mediated antigen can induce an effective immune response against tumor cells in vivo, with contributions from both humoral and cellular immunity. This work suggests that yeast shell microparticles as efficient vaccine delivery system has promising applications in cancer immunotherapy.

Functional Nanoparticles Activate a Decellularized Liver Scaffold for Blood Detoxification.

Extracorporeal devices have great promise for cleansing the body of virulence factors that are caused by venomous injuries, bacterial infections, and biological weaponry. The clinically used extracorporeal devices, such as artificial liver-support systems that are mainly based on dialysis or electrostatic interaction, are limited to remove a target toxin. Here, a liver-mimetic device is shown that consists of decellularized liver scaffold (DLS) populated with polydiacetylene (PDA) nanoparticles. DLS has the gross shape and 3D architecture of a liver, and the PDA nanoparticles selectively capture and neutralize the pore-forming toxins (PFTs). This device can efficiently and target-orientedly remove PFTs in human blood ex vivo without changing blood components or activating complement factors, showing potential application in antidotal therapy. This work provides a proof-of-principle for blood detoxification by a nanoparticle-activated DLS, and can lead to the development of future medical devices for antidotal therapy.

A 3D‐Engineered Conformal Implant Releases DNA Nanocomplexs for Eradicating the Postsurgery Residual Glioblastoma

Gene therapy has great promise for glioblastoma treatment; however, it remains a great challenge to efficiently deliver genes to the brain. The incomplete resection of glioblastoma always leads to poor prognosis. Here, a 3D‐engineered conformal implant for eradicating the postsurgery residual glioblastoma is designed. This implant is constructed by 3D‐printing technology to match the tumor cavity and release an oncolytic virus‐inspired DNA nanocomplex to kill glioblastoma cells through apoptosis induction. Meanwhile, a 3D‐engineered subcutaneous glioblastoma xenograft is built to mimic the resection tumor cavity in mice. Insertion of the implant into the glioblastoma resection cavity efficiently delays tumor recurrence and significantly prolongs overall survival. This study provides a proof‐of‐concept of glioblastoma therapy using a conformal implant that releases oncolytic DNA nanocomplexs. This strategy can lead to the development of future precision therapy for eradicating postsurgery residual tumors.

Ovarian Cancer Therapy by VSVMP Gene Mediated by a Paclitaxel-Enhanced Nanoparticle

Nanoparticles have great promise for gene delivery. However, the transfection efficiency of nanoparticle-based gene delivery systems is always unsatisfied to meet the requirement of effective gene therapy. Herein, we used low-dosage paclitaxel to enhance a nanoscaled gene delivery system that was self-assembled from N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethylammoniummethyl sulfate and monomethoxy poly(ethylene glycol)-poly(d,l-lactide) (DPP), creating a paclitaxel-encapsulated DPP (P-DPP) nanoparticle. The encapsulated low-dosage paclitaxel significantly improved the gene delivery efficiency of the DPP nanoparticles against multiple cancer cells, in some of which the transfection efficiency is as high as 92%. By the P-DPP nanoparticle, vesicular stomatitis virus matrix protein (VSVMP) that could induce cell apoptosis was delivered to treat ovarian cancer. The encapsulation of paclitaxel in DPP nanoparticles increased the expression of VSVMP, enhancing VSVMP to induce antiproliferation and apoptosis in SKOV3 ovarian cancer cells. Intraperitoneal administration of P-DPP-delivered VSVMP effectively inhibited the intraperitoneal metastasis of SKOV3 ovarian cancer, which was more efficient than DPP-delivered VSVMP. Moreover, it was found that the tumor cell apoptosis induction, tumor cell proliferation inhibition, and tumor angiogenesis suppression were involved in the anticancer mechanism of this nanocomplex. Our data suggest that the encapsulation of low-dosage paclitaxel can enhance the gene delivery efficiency of the DPP nanoparticles against multiple cancer cells and exert a synergistic anticancer effect with VSVMP gene in ovarian cancer treatment. The VSVMP gene therapy delivered by the paclitaxel-enhanced nanoparticle has potential application in ovarian cancer therapy.

A biomimetic nanoparticle-enabled toxoid vaccine against melittin

Background Melittin, the main active peptide ingredient of bee venom, can cause severe cell membrane lysis due to its robust interaction with negatively charged phospholipids. So far, no effective anti-melittin vaccine has been developed to protect people from undesired melittin intoxication. Methods Herein, we prepared a polydiacetylene (PDA) nanoparticle with cell membrane-mimic surface to complex melittin, forming an anti-melittin vaccine (PDA–melittin). Results PDA nanoparticles could effectively combine with melittin and neutralize its toxicity. PDA–melittin nanocomplex is demonstrated to enhance melittin uptake by DCs and stimulate strong melittin-specific immunity. Mice immunized with PDA–melittin nanocomplex showed higher survival rate after exposion to melittin than untreated mice. Conclusion The PDA–melittin nanocomplex can efficiently and safely generate a specific immunity against melittin to protect body from melittin intoxication, providing a new method with potential clinical application for the treatment of melittin intoxication.

A Vesicular Stomatitis Virus‐Inspired DNA Nanocomplex for Ovarian Cancer Therapy

Abstract Gene therapy provides a novel method for cancer therapy. This study shows a DNA nanocomplex that is inspired from vesicular stomatitis virus (VSV) for ovarian cancer therapy. This DNA nanocomplex consists of a cationized monomethoxy poly (ethylene glycol)‐poly (d,l‐lactide) (MPEG‐PLA) nanoparticle and a plasmid encoding the matrix protein of vesicular stomatitis virus (VSVMP) that plays a critical role in the VSV‐induced apoptosis of cancer cells. The cationized MPEG‐PLA nanoparticle that is self‐assembled by MPEG‐PLA copolymer and N‐[1‐(2,3‐dioleoyloxy) propyl]‐N,N,N‐trimethylammonium chloride (DOTAP) has low cytotoxicity and high transfection efficiency (>80%). Intraperitoneal administration of the pVSVMP nanocomplex remarkably inhibits the intraperitoneal metastasis of ovarian cancer and does not cause significant systemic toxicity. The apoptosis induction and anti‐angiogenesis are involved in the anticancer mechanism. This work demonstrates a VSV‐inspired DNA nanocomplex that has potential application for the treatment of intraperitoneal metastasis of ovarian cancer.