PAA nanoparticles for enhancement of tumor imaging

A composition comprising PAA nanoparticles containing a tetrapyrollic photosensitizer and an imaging agent, wherein the tetrapyrollic photosensitizer has the structural formula:

• or a pharmaceutically acceptable derivative thereof, wherein:
• R1 and R2 are each independently substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, —C(O)Ra or —COORa or —CH(CH3)(ORa) or —CH(CH3)(O(CH2)nXRa) where Ra is hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl, or substituted or unsubstituted cycloalkyl;
• where R2 may be —CH═CH2, —CH(OR20)CH3, —C(O)Me, —C(═NR21)CH3 or —CH(NHR21)CH3
• where X is an aryl or heteroaryl group;
• n is an integer of 0 to 6;
• where R20 is methyl, butyl, heptyl, docecyl or 3,5-bis(trifluoromethyl)-benzyl;
• and
• R21 is 3,5,-bis(trifluoromethyl)benzyl;
• R1a and R2a are each independently hydrogen or substituted or unsubstituted alkyl, or together form a covalent bond;
• R3 and R4 are each independently hydrogen or substituted or unsubstituted alkyl;
• R3a and R4a are each independently hydrogen or substituted or unsubstituted alkyl, or together form a covalent bond;
• R5 is hydrogen or substituted or unsubstituted alkyl;
• R6 and R6a are each independently hydrogen or substituted or unsubstituted alkyl, or together form ═O;
• R7 is a covalent bond, alkylene, azaalkyl, or azaaraalkyl or ═NR20 where R20 is 3,5-bis(tri-fluoromethyl)benzyl or —CH2X—R1 or —YR1 where Y is an aryl or heteroaryl group;
• R8 and R8a are each independently hydrogen or substituted or unsubstituted alkyl or together form ═O;
• R9 and R10 are each independently hydrogen, or substituted or unsubstituted alkyl and R9 may be —CH2CH2COOR2 where R2 is an alkyl group that may optionally substituted with one or more fluorine atoms;
• each of R1-R10, when substituted, is substituted with one or more substituents each independently selected from Q, where Q is alkyl, haloalkyl, halo, photosensitizereudohalo, or —COORb where Rb is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, araalkyl, or ORc where Rc is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or aryl or CONRdRe where Rd and Re are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or NRfRg where Rf and Rg are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or ═NRh where Rh is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or is an amino acid residue;
• each Q is independently unsubstituted or is substituted with one or more substituents each independently selected from Q1, where Q1 is alkyl, haloalkyl, halo, photosensitizereudohalo, or —COORb where Rb is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, aryl, heteroaryl, araalkyl, or ORc where Rc is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or aryl or CONRdRe where Rd and Re are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or NRfRg where Rf and Rg are each independently hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or ═NRh where Rh is hydrogen, alkyl, alkenyl, alkynyl, cycloalkyl, or aryl, or is an amino acid residue.
• wherein the photosensitizer is postloaded onto the nanoparticle after nanoparticle formation.