Related Experiment Video
Updated: May 10, 2026

Facile Preparation and Photoactivation of Prodrug-Dye Nanoassemblies
Published on: February 17, 2023
Protoporphyrin IX-β-cyclodextrin bimodal conjugate: nanosized drug transporter and potent phototoxin
Chrysie Aggelidou1, Theodossis A Theodossiou, Konstantina Yannakopoulou
1Institute of Advanced Materials, Physicochemical Processes, Nanotechnology & Microsystems, National Center for Scientific Research "Demokritos", Aghia Paraskevi, Attiki, Greece.
Abstract:
Topical or systemic administration of 5-aminolevulinic acid (ALA) and its esters results in increased production and accumulation of protoporphyrin IX (PpIX) in cancerous lesions allowing effective application of photodynamic therapy (PDT). The large concentrations of exogenous ALA practically required to bypass the negative feedback control exerted by heme on enzymatic ALA synthesis and the strong dimerization propensity of ALA are shortcomings of the otherwise attractive PpIX biosynthesis. To circumvent these limitations and possibly enhance the phototoxicity of PpIX by adjuvant chemotherapy, covalent bonding of PpIX with a drug carrier, β-cyclodextrin (βCD) was implemented. The resulting PpIX + βCD product had both carboxylic termini of PpIX connected to the CD. PpIX + βCD was water soluble, was found to preferentially localize in mitochondria rather than in lysosomes both in MCF7 and DU145 cell lines while its phototoxiciy was comparable to that of PpIX. Moreover, PpIX + βCD effectively solubilized the breast cancer drug tamoxifen metabolite N-desmethyltamoxifen (NDMTAM) in water. The PpIX + βCD/NDMTAM complex was readily internalized by both cell lines employed. Furthermore, the multimodal action of PpIX + βCD was demonstrated in MCF7 cells: while it retains the phototoxic profile of PpIX and its fluorescence for imaging purposes, PpIX + βCD can efficiently transport tamoxifen citrate intracellularly and confer cell death through a synergy of photo- and chemotoxicity.
Related Concept Videos
Photoreceptors and Visual Pathways
Site-Targeted Drug Delivery Systems: Polymeric Carriers
Drug Biotransformation: Overview
Modified-Release Drug Delivery Systems: Site-Targeted
Carrier-Mediated Transport
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Pore Transport and Ion-Pair Transport
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...

