Lowess smoothing at the edge of a dataset

Hi all,

I am currently trying to use Matlab to replicate a graph produced in Prism. However, it seems that Matlab does something strange when you smooth the data at the edge of a dataset.

Example in Prism:

Example in Matlab:

Notes: The blue line is Lowess smoothed with a window of 10 points and then splined.

Any help with this matter would be HUGELY appreciated. Perhaps Prism has a trick for filling in datapoints on the edge (the first 4 or 5?)

Thank you!