Stem cell therapy has emerged as a promising approach for treatment of a number of diseases, including delayed and non-healing wounds. However, targeted systemic delivery of therapeutic cells to the dysfunctional tissues remains one formidable challenge. Herein, we present a targeted nanocarrier-mediated cell delivery method by coating the surface of the cell to be delivered with dendrimer nanocarriers modified with adhesion molecules. Infused nanocarrier-coated cells reach to destination via recognition and association with the counterpart adhesion molecules highly or selectively expressed on the activated endothelium in diseased tissues. Once anchored on the activated endothelium, nanocarriers-coated transporting cells undergo transendothelial migration, extravasation and homing to the targeted tissues to execute their therapeutic role. We now demonstrate feasibility, efficacy and safety of our targeted nanocarrier for delivery of bone marrow cells (BMC) to cutaneous wound tissues and grafted corneas and its advantages over conventional BMC transplantation in mouse models for wound healing and neovascularization. This versatile platform is suited for targeted systemic delivery of virtually any type of therapeutic cell.

PDD reduced the effective dose and toxicity of LAmB and resulted in elicitation of strong parasite specific T-cell responses. A reduced effective therapeutic dose was achieved by selective LAmB delivery to APC, bypassing bystander cells, reducing toxicity and inducing antiparasite immunity.

Here we describe the design and construction of an imaging construct with high bioluminescent resonance energy transfer (BRET) efficiency that is comprised of multiple quantum dots (QDs, λem 655 nm) self-assembled onto a bioluminescent protein, Renilla luciferase (Rluc). This is facilitated by the streptavidin-biotin interaction, allowing the facile formation of a hybrid-imaging-construct (HIC) comprising up to 6 QDs (acceptor) grafted onto a light emitting Rluc (donor) core. The resulting assembly of multiple acceptors surrounding a donor permits this construct to exhibit high resonance energy transfer efficiency (~64.8%). The HIC was characterized using fluorescence excitation anisotropy measurements and high resolution transmission electron microscopy. To demonstrate the application of our construct, a generation-5 (G5) polyamidoamine dendrimer (PAMAM) nanocarrier was loaded with our HIC for in vitro and in vivo imaging. We envision that this design of multiple acceptors and bioluminescent donor would lead to the development of new BRET-based systems useful in sensing, imaging, and other bioanalytical applications.

Introduction: Stem cell therapy has emerged as a promising approach for treatment of a number of diseases, including delayed and non-healing wounds. However, targeted systemic delivery of therapeutic cells to the dysfunctional tissues remains one formidable challenge. Methods: We have developed a targeted nanocarrier-mediated cell delivery method by coating the surface of the cell to be delivered with dendrimer nanocarriers modified with adhesion molecules. Infused nanocarrier-coated cells reach to destination via recognition and association with the counterpart adhesion molecules highly or selectively expressed on the activated endothelium in diseased tissues. Once anchored on the activated endothelium, nanocarriers-coated transporting cells undergo transendothelial migration, extravasation and homing to the targeted tissues to execute their therapeutic role. Wound healing was measured by digital photograph and ImageJ calculation. Targeted tissue homing of LacZ + bone marrow cells (BMC) was detected and quantified by X-gal staining, and BMC-enhanced neovascularization was examined by Dil perfusion and scanning confocal microscopy. Results: Soluble E-selectin (sE-sel) was successful installed on BMC surface by dendrimer nanocarriers. sE-sel-nanocarriers can associate with E-selectin ligands highly expressed on the wound endothelium, by which coated BMC are targeted delivered to skin wound tissues and grafted corneas to promote wound healing and neovascularization. Conclusions: We demonstrate feasibility, efficacy and safety of our targeted nanocarrier for delivery of BMC to cutaneous wound tissues and grafted corneas and its advantages over conventional BMC transplantation in mouse models for wound healing and neovascularization. This versatile platform is suited for targeted systemic delivery of virtually any type of therapeutic cell.

Objectives: Wound healing and angiogenesis are impaired in patients with diabetes and peripheral vascular disease. We developed a novel treatment by systemic administration of mesenchymal stem cells (MSC) coated with nanocarrier composed of adhesion molecule -nanoparticle complex (AMNC). AMNC-MSC significantly enhanced wound healing and angiogenesis, in wild type and diabetic mice. AMNC-MSC targeted homing is specific to the injured tissue and superior to BSA (control)-NC coating or uncoated MSC. We now investigate the biosafety profile of the AMNC-MSC. Method: 1x 10 6 HUVEC were coated with AMNC. Cytotoxicity of AMNC was evaluated by trypan blue. Cell apoptosis was analyzed by flow cytometry using FITC-Annexin-V and propidium iodide. 12-14 week-old C57BL6 mice (N=15) underwent 6mm full thickness dorsal dermal wounding and then assigned to 3 IV treatment groups: (i) 1x 10 6 AMNC-MSC, (ii) 1x 10 6 MSC and (iii) equivalent volume saline (No Treatment (NT); (n=5/group). Day 8 post-wounding and treatment, comprehensive metabolic panel, complete blood count and urinalysis were obtained. Result: AMNC-MSC had no cytotoxicity to HUVEC. Blood tests and urinalysis revealed that the hematological, hepatic, renal and pancreatic functions were normal in all groups. Hyperglycemia was observed among all groups at comparable level (p=0.136), likely a stress response. All other blood/urine parameters were within normal, in all groups. Conclusion: AMNC-MSC has no observed cytotoxicity to human endothelial cells, in vitro . Intravenous administration of AMNC-MSC does not cause metabolic or hematologic toxicity, in mice. We demonstrate initial biosafety of novel nanocarrier-targeted MSC therapy which holds promise in pro-angiogenic and pro-healing regenerative medicine.