Abdel Chakiri

Abdel Chakiri coauthored a 2015 study with Philip Hodge on ring-opening metathesis polymerization of macrocyclic olefins prepared from deoxycholic acid. The primary manuscript gives the Manchester chemistry affiliation and describes functionalized polymers and film formation.^[ref]

The scientific idea is to use molecular building blocks that carry useful functional groups into the resulting polymer, rather than treating the chain backbone as the only design variable. A polymer repeat unit can describe a recurring structural contribution, while the final material also depends on its chain lengths, end groups and retained functionality.

For an original bookkeeping example, suppose an ideal polymerization converts 100 macrocyclic building blocks into long chains without losing their repeat-unit mass, and each building block carries two accessible hydroxyl groups. The product contains 200 such groups regardless of whether it forms one chain or ten. If the repeat contribution is $500\mathrm{g}\mathrm{mo}{\mathrm{l}}^{-1}$, that corresponds to $2/500=4\mathrm{mmol}{\mathrm{g}}^{-1}$ of groups in the end-group-neglecting model. Changing the number of chains changes average molecular size but not that stipulated functional-group loading.

The assumption of two surviving accessible groups per unit must be tested, not inferred from a synthetic scheme alone. Spectroscopy or chemical analysis can examine structure; film formation and mechanical testing examine different properties. The manuscript's proposed use of films for supporting cell growth should likewise be distinguished from a demonstrated biological or clinical result. The numerical loading above is illustrative and is not assigned to Chakiri's actual polymers.