David L. Kaplan

David L. Kaplan co-authored experimental papers with Michael Levin on how membrane voltage acts on cells. The held works cover depolarization of human mesenchymal stem cells¹², a silk hydrogel device for frog limb regeneration³⁴, and ionic solutions for setting resting potential⁵⁶.

Born: 18 March 1953
Country: United States
Field: biomedical engineer
In the library: 8 works, named in 6 passages elsewhere
Facts from: Wikidata · Wikipedia · ORCID

Depolarization of stem cells

Sundelacruz, Levin and Kaplan (2015) compared how human mesenchymal stem cells from five donors responded to depolarization. They noted that earlier efforts had not systematically assessed this variability, which matters for primary cells that differ between donors¹. They added HK to cells already differentiated into osteoblasts and measured ALPL and IBSP expression, ALP activity and calcification on Day 21. ALP activity proved an inconsistent marker. It was the same, higher or lower in osteogenic cells depending on the donor, and depolarization had no significant effect in four of five donors². A 2017 planarian paper listed the 2009 Sundelacruz, Levin and Kaplan work among studies of bioelectric signalling in many model systems⁷.

A silk device for frogs

Golding and colleagues (2016) built a silk hydrogel device for studying limb regeneration in adult Xenopus laevis. They described the frog as like the axolotl and zebrafish in regenerating limbs, but its ability wanes with development. After about stage 61 the animal forms a cartilage spike instead of a limb³. They also argued that the frog is a bridge to the mouse, because fibroblasts rebuild tissue in both. The silk was cross-linked at tyrosine side chains with horseradish peroxidase⁴. The device was stitched to the amputated limb over a rubber wrap.

Setting resting potential

Bonzanni and colleagues (2020), with Kaplan and Levin among the authors, described resting potential as set by membrane permeability and the gradients of Na+, K+ and Cl−, and calculated by the Goldman-Hodgkin-Katz equation. They used defined ionic solutions with a voltage-sensitive dye. MDA-MB-231 breast cancer cells gave 1.28±0.11 F/mV. The authors concluded that calibration curves are cell-line specific⁶. Later, Mathews and colleagues (2022) differentiated human neural stem cells given to them by Kaplan⁸.

SourcesEach quotation was checked word for word against the passage it opens.

efforts toward this end have not included a systematic assessment of the heterogeneity of hMSC response to bioelectric signalsSundelacruz S, Levin M, Kaplan DL, 2015 · Comparison of the depolarization response of human mesenchymal stem cells from… · open at passage 4
we found ALPL activity to again be an inconsistent osteogenic marker: osteogenic cells were found to have the same, increased, or decreased enzyme activity relative to undifferentiated cells in the five donorsSundelacruz S, Levin M, Kaplan DL, 2015 · Comparison of the depolarization response of human mesenchymal stem cells from… · open at passage 19
this innate regenerative ability wanes as the animal develops. After about stage 61 of development, tissue growth does not provide the morphological characteristics of a limb, rather the animal forms a cartilage spikeGolding A, Guay JA, Herrera-Rincon C, Levin M, Kaplan DL, 2016 · A Tunable Silk Hydrogel Device for Studying Limb Regeneration in Adult Xenopus… · open at passage 4
This was then enzymatically cross-linked at the tyrosine side chains using horseradish peroxidase enzyme (HRP) at 20 U/mlGolding A, Guay JA, Herrera-Rincon C, Levin M, Kaplan DL, 2016 · A Tunable Silk Hydrogel Device for Studying Limb Regeneration in Adult Xenopus… · open at passage 12
The slope of the resulting linear fit indicates the change in the fluorescence value per unit of voltage change (ΔF/ΔV), shown to be 1.76±0.19 F/mV for RPTECs.Bonzanni M, Payne SL, Adelfio M, Kaplan DL, Levin M, Oudin…, 2020 · Defined extracellular ionic solutions to study and manipulate the cellular… · open at passage 11
These data demonstrate that calibration curves are cell-line specific and can be used to identify the differential effect of ion concentration on the RMPBonzanni M, Payne SL, Adelfio M, Kaplan DL, Levin M, Oudin…, 2020 · Defined extracellular ionic solutions to study and manipulate the cellular… · open at passage 12
many other model systems (Bates, 2015; Levin, 2007, 2014b; Levin & Stevenson, 2012; Sundelacruz, Levin, & Kaplan, 2009)Morokuma J, Durant F, Williams KB, Finkelstein JM…, 2017 · Planarian regeneration in space: Persistent anatomical, behavioral, and… · open at passage 28
Human neuronal cells were differentiated from human induced neural stem cells (hiNSCs) (passage 7–10), a generous gift from David KaplanMathews J, Kuchling F, Baez-Nieto D, Diberardinis M, Pan…, 2022 · Ion Channel Drugs Suppress Cancer Phenotype in NG108-15 and U87 Cells: Toward… · open at passage 13