A study has shown that a peptide wrapped in a fatty liposome capsule can deliver chemotherapy drugs deep into tumour sites.
University of Minnesota researcher Hongbo Pang led a cross-institutional study on improving the efficacy of nucleotide-based drugs against prostate cancer and bone metastasis.
The researchers looked at whether liposomes (enclosures of fatty molecules), when integrated with the iRGD peptide (which binds strongly to tumour blood vessels), will help concentrate antisense oligonucleotides (ASOs, a type of nucleolytic drug) into primary prostate tumours and its bone metastases.
More importantly, they investigated whether this system helps more drugs across the vessel wall and deeply into the tumor tissue. This is critical because, although nucleotide drugs have unique advantages in treating tumours and other diseases, they often struggle to cross the blood vessels and penetrate the tumour tissue, where their targets reside. Their clinical applicability and efficacy is hampered as a result. Even typical chemotherapeutic agents only penetrate 3-5 cancer cell diameters deep.
“Our system demonstrates a good ability to deliver more ASOs into both primary tumor tissue and bone metastases — which is the primary site for prostate cancer metastasis. This further translates into a significant improvement of ASO efficacy to inhibit the growth of primary tumor and bone metastases,” said study leader Hongbo Pang, assistant professor at the College of Pharmacy, and member of the Masonic Cancer Center. “We expect this system to become a universal carrier system, to improve the clinical efficacy of ASOs and other nucleotide drugs.”
The study found that iRGD-liposomes can increase the tumor accumulation and vascular/tissue penetration of ASOs against the disease-driving gene of prostate cancer. It also found that the ability of ASOs to inhibit primary tumours and bone metastases growth was significantly improved with iRGD-liposomes. A long-term tumour inhibition study was also performed, which showed that iRGD-liposomes significantly extends the AR-ASO suppression of primary tumor growth.
Pang and his team concluded that iRGD-liposomes are proven as a desirable delivery system for ASOs, and could enhance the clinical efficacy of nucleotide drugs in cancer therapies.
Source: News-Medical.Net
Journal information: Guan, J., et al. (2021) iRGD‐Liposomes Enhance Tumor Delivery and Therapeutic Efficacy of Antisense Oligonucleotide Drugs against Primary Prostate Cancer and Bone Metastasis. Advanced Functional Materials. doi.org/10.1002/adfm.202100478.
