( ( ( ( ( ( ( Most particles ) ( that ( do penetrate ) ) ) ( will ( diffuse ( through ( skin cells ) ) ) ) ) , ) but ) ( some ( will ( ( ( ( travel down ) ( hair follicles ) ) and ) ( reach ( the ( dermis layer ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (NP (JJS Most) (NNS particles)) (SBAR (WHNP (WDT that)) (S (VP (VBP do) (VP (VB penetrate)))))) (VP (MD will) (VP (VB diffuse) (PP (IN through) (NP (NN skin) (NNS cells)))))) (, ,) (CC but) (S (NP (DT some)) (VP (MD will) (VP (VP (VB travel) (PRT (RP down)) (NP (NN hair) (NNS follicles))) (CC and) (VP (VB reach) (NP (DT the) (JJ dermis) (NN layer)))))) (. .)))
Most particles that do penetrate will diffuse through skin cells, but some will travel down hair follicles and reach the dermis layer.
(ROOT (S (NP (JJS Most) (NN skin) (NNS structures)) (VP (VB originate) (PP (IN in) (NP (DT the) (NNS dermis)))) (. .)))