Flexible-Structured Cyanine-Cyanine Conjugate Affords Highly Efficient Photothermal Therapy via Enhanced Tumor
Yanxian Hou1, Yinhao Lin1, Linying Wang1
1Wenzhou Municipal Key Laboratory of Pediatric Pharmacy, Department of Pharmacy, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, Wenzhou 325027, China.
Abstract:
Simultaneous optimization of tumor accumulation and photothermal conversion efficiency (PCE) remains a major challenge in photothermal agent (PTA) development. Here, benzene-thiol/-dithio/-trithiol was introduced at the meso-position of heptamethine cyanine (Cy7) via sulfhydryl substitution. The obtained derivatives, denoted as M-Cy7, D-Cy7, and T-Cy7, conferred enhanced molecular flexibility, promoting self-assembly and passive tumor accumulation. Although increasing the number of Cy7 units reduced molecular flexibility in the D- and T-derivatives, the central phenyl linker enabled covalent coupling of intramolecular Cy7 moieties, resulting in a "covalent aggregation" effect and boosting PCE to 77%─nearly seven times higher than that of the prototypic Cy7. Among them, D-Cy7 demonstrated the most favorable balance of tumor accumulation and photothermal efficiency, achieving optimal in vivo PTT efficacy. This novel molecular design strategy successfully integrated high PCE and tumor-targeting capability into a single PTA, offering new insights for advancing photothermal therapy.
More Related Videos
Related Concept Videos
Structure of Conjugated Dienes
Conjugated dienes are compounds characterized by the presence of alternating double and single bonds. In a conjugated system like 1,3-butadiene, the unhybridized 2p orbital on each carbon overlaps continuously, allowing the π electrons to be delocalized across the entire molecule. In contrast, this type of overlap does not occur in cumulated and isolated dienes, such as 2,3-pentadiene and 1,4-pentadiene, respectively. Instead, the π electrons remain localized between the double...
Conjugated Proteins
Nucleoproteins are protein complexes that contain nucleic acids, categorized as deoxyribonucleoproteins (DNPs) or ribonucleoproteins (RNPs) respectively. The nucleosome is a typical example of a DNP where nuclear DNA is associated with histone proteins. The major antigen for the Covid-19 virus SARS-CoV is an RNP that is critical...
Conjugated Proteins
Responses to Heat and Cold Stress
Specific Heat
For example, increasing the temperature of one gram of water by 1°C requires one calorie of heat energy and can be written as 1 cal/g-°C, or...
Quantifying Heat


