Comparison of aluminium (III) phthalocyanine tetrasulfonate- and meta-tetrahydroxyphenylchlorin-monoclonal antibody conjugates for their efficacy in photodynamic therapy in vitro.

A challenge in photodynamic therapy (PDT) is to improve the tumour selectivity of the photosensitizers by using monoclonal antibodies (MAbs). With this aim, we developed MAb-conjugates with the hydrophobic photosensitizer meta-tetrahydroxyphenylchlorin (mTHPC) and with the hydrophilic sensitizer aluminium (III) phthalocyanine tetrasulfonate (AlPcS(4)). The capacity of these photoimmunoconjugates for selective targeting of squamous cell carcinoma (SCC) in vivo was demonstrated previously in SCC-bearing nude mice.