There are also still lots of basic research to be done too..

For example, how a cell controls its membrane surface area are is not known. Some cells, especially secretory and phagocytic cells, change their membrane surface area constantly, by either fusing vesicles to the membrane to secrete substances (such as endocrine cells, nerve cells, exocrine cells, etc.) or engulfing substances by wrapping the membrane around what's to be engulfed (like macrophages).

Cells that secrete constantly adds surface area to the membrane as vesicles fuse to them, and cells that phagocytize constantly subtracts surface area from the cell membrane by infolding vesicles into its cytoplasm. How they maintain their cell membrane within a tolerable operating range is not known.

If the membrane surface area control mechanism can be elucidated, I think it would provide a possible answer to the effects of nanobots increasing a cell's volume.