BACKGROUND: Autologous fat is the ideal soft-tissue filler; however, its widespread application is limited because of variable clinical results and poor survival. Engineered fillers have the potential to maximize survival. Alginate is a hydrogel copolymer that can be engineered into spheres of <200 μm, thus facilitating mass transfer, allowing for subcutaneous injection, and protecting cells from shearing forces. METHODS: Alginate powder was dissolved in saline, and adipose-derived stem cells (ADSCs) were encapsulated (1 million cells/mL) in alginate using an electrostatic bead generator. To assess effects of injection on cell viability, microspheres containing ADSCs were separated into 2 groups: the control group was decanted into culture wells and the injection group was mixed with basal media and injected through a 21-gauge needle into culture wells. Microbeads were cultured for 3 weeks, and cell number and viability were measured weekly using electron and confocal microscopy. To assess effects of percutaneous injection in vivo, twenty-four male nude mice were randomly separated into 2 groups and injected with either empty microcapsules or ADSC-laden microcapsules. Mice were harvested at 1 and 3 months, and the implants were examined microscopically to assess bead and cell viability. RESULTS: A flow rate of 5 mL/h and an electrostatic potential of 7 kV produced viable ADSC-laden microbeads of <200 μm. There were no differences in bead morphology and ADSC viability between microcapsules placed versus injected into tissue culture plates for up to 3 weeks. Microspheres implanted in a nude mouse model show durability up to 3 months with a host response around each individual sphere. ADSCs remained viable and showed signs of mitosis. CONCLUSIONS: ADSCs can be readily cultured, encapsulated, and injected in alginate microspheres. Stem cells suspended in alginate microspheres survive in vivo and are seen to replicate in vitro.
BACKGROUND: Autologous fat is the ideal soft-tissue filler; however, its widespread application is limited because of variable clinical results and poor survival. Engineered fillers have the potential to maximize survival. Alginate is a hydrogel copolymer that can be engineered into spheres of <200 μm, thus facilitating mass transfer, allowing for subcutaneous injection, and protecting cells from shearing forces. METHODS:Alginate powder was dissolved in saline, and adipose-derived stem cells (ADSCs) were encapsulated (1 million cells/mL) in alginate using an electrostatic bead generator. To assess effects of injection on cell viability, microspheres containing ADSCs were separated into 2 groups: the control group was decanted into culture wells and the injection group was mixed with basal media and injected through a 21-gauge needle into culture wells. Microbeads were cultured for 3 weeks, and cell number and viability were measured weekly using electron and confocal microscopy. To assess effects of percutaneous injection in vivo, twenty-four male nude mice were randomly separated into 2 groups and injected with either empty microcapsules or ADSC-laden microcapsules. Mice were harvested at 1 and 3 months, and the implants were examined microscopically to assess bead and cell viability. RESULTS: A flow rate of 5 mL/h and an electrostatic potential of 7 kV produced viable ADSC-laden microbeads of <200 μm. There were no differences in bead morphology and ADSC viability between microcapsules placed versus injected into tissue culture plates for up to 3 weeks. Microspheres implanted in a nude mouse model show durability up to 3 months with a host response around each individual sphere. ADSCs remained viable and showed signs of mitosis. CONCLUSIONS: ADSCs can be readily cultured, encapsulated, and injected in alginate microspheres. Stem cells suspended in alginate microspheres survive in vivo and are seen to replicate in vitro.
Authors: Christopher S D Lee; Elyse Watkins; Olivia A Burnsed; Zvi Schwartz; Barbara D Boyan Journal: Tissue Eng Part A Date: 2013-03-28 Impact factor: 3.845
Authors: Christopher S D Lee; Anthony M Nicolini; Elyse A Watkins; Olivia A Burnsed; Barbara D Boyan; Zvi Schwartz Journal: J Stem Cells Regen Med Date: 2014-11-28
Authors: Mong-Jen Chen; Yuanqing Lu; Nicholas E Simpson; Mark J Beveridge; Ahmed S Elshikha; Mohammad Ahsanul Akbar; Hsin-Yin Tsai; Stephanie Hinske; Junling Qin; Christian R Grunwitz; Tina Chen; Mark L Brantly; Sihong Song Journal: PLoS One Date: 2015-09-15 Impact factor: 3.240
Authors: Christopher Sd Lee; Olivia A Burnsed; Vineeth Raghuram; Jonathan Kalisvaart; Barbara D Boyan; Zvi Schwartz Journal: Stem Cell Res Ther Date: 2012-08-24 Impact factor: 6.832