{HEAD ~ The development} of more specialized methods due to {TAIL ~ the differences} in cell density, water content and level of structural organization of the full thickness LSE was required 
due to
{ HEAD ~ The development } of more specialized methods due to { TAIL ~ the differences } in cell density , water content and level of structural organization of the full thickness LSE was required
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH