Navigation Links
New cancer drug delivery system is effective and reversible

CHAMPAIGN, Ill. For cancer drug developers, finding an agent that kills tumor cells is only part of the equation. The drug must also spare healthy cells, and ideally its effects will be reversible, to cut short any potentially dangerous side effects.

University of Illinois researchers report that they have assembled a new cancer drug delivery system that, in cell culture, achieves all of the above. The findings appear this month in the journal Angewandte Chemie.

The team began with the knowledge that small, membrane-bound compartments, called liposomes, are useful as drug-delivery vehicles. When linked to molecules that target receptors on cancer cells, liposomes can enter and dump their cancer-killing contents into those cells.

Scientists have spent more than a decade trying to direct liposomes to specific cancer cells, with limited success. A common approach involves attaching an antibody to the liposome membrane. Ideally the antibody will bind to a cancer cell receptor so that it can deliver the liposome and the cancer drug into the cell.

Developing such antibodies is costly and time-consuming, however, and the process of attaching them to liposomes is difficult to control. Antibodies spur an immune response, requiring extra steps to create a useable therapeutic agent, and the ability of antibody-conjugated liposomes to bind to cancer cells can be inconsistent.

Some small molecules, such folate, a vitamin, also work as cancer cell targeting agents, but those now in use are not as good as antibodies at binding to cancer cells.

To solve the cell-targeting problem, the U. of I. team turned its attention to small molecules called aptamers.

"Aptamers are short strands of DNA or RNA; they are highly efficient binders, and are very easy to make, label and manipulate," said Zehui Cao, a postdoctoral researcher in the laboratory of chemistry professor Yi Lu, who led the study. Materials science and engineering professors Gerard Wong and Jianjun Cheng were co-principal investigators on the study with Lu. Graduate students Rong Tong (who is co-first author on the paper with Cao), Abhijit Mishra and Weichen Xu also worked on the study.

Lu's laboratory specializes in isolating aptamers that bind to specific molecules and converting them into effective sensors and diagnostic agents. His team used an aptamer that binds to nucleolin receptors, which are found in abundance on certain breast cancer cells. The researchers then developed an effective method for attaching the aptamer to a liposome loaded with cisplatin, a drug that effectively kills cancer cells but has troublesome side effects when administered intravenously.

Tests in cells grown in the lab yielded promising results. Four days after they exposed the cells to the new drug-delivery system, 59.5 percent of the breast cancer cells had died, while less than 12 percent of breast cancer cells treated with cisplatin alone had died.

"By labeling a liposome that contains cisplatin with a cancer cell-specific aptamer, we have shown delivery of the drugs to cancer cells without significant damage to regular cells," Lu said, "making it possible to maximize the drug potency while minimizing its side effects."

This approach "integrates the advantages of small molecules and antibodies," said Cheng, who helped pioneer the use of aptamers as targeting molecules for drug delivery. "This is the first study to integrate the aptamers and the liposome."

Another advantage of using aptamers as targeting agents is that they are easily disabled. They readily bind to complementary DNA, which prevents them from interacting with cell receptors.

The new approach will be useful for many applications, Wong said. "What we're really doing here is coming up with a general toolbox to deal with a broad range of cancers."

"You can change aptamers to target a different type of cancer, you can change the therapeutic molecules to fight cancer or other diseases, and you can reverse the dose," Cheng said. "That's a lot of tools in the toolbox. It has great potential."


Contact: Diana Yates
University of Illinois at Urbana-Champaign

Related biology news :

1. Protein handlers should be effective treatment target for cancer and Alzheimers
2. Moving to the US increases cancer risk for Hispanics
3. Women often opt to surgically remove their breasts, ovaries to reduce cancer risk
4. Pitt researchers find promising candidate protein for cancer prevention vaccines
5. The way you eat may affect your risk for breast cancer
6. Stem cell daughters lead to breast cancer
7. Study links virus to some cases of common skin cancer
8. A crystal ball for brain cancer?
9. Fox Chase researchers uncover one force behind the MYC oncogene in many cancers
10. Study shows cancer vaccines led to long-term survival for patients with metastatic melanoma
11. Cancers distinctive pattern of gene expression could aid early screening and prevention
Post Your Comments:
Related Image:
New cancer drug delivery system is effective and reversible
(Date:11/12/2015)... 11, 2015   Growing need for low-cost, ... has been paving the way for use of ... discrete analytes in clinical, agricultural, environmental, food and ... used in medical applications, however, their adoption is ... to continuous emphasis on improving product quality and ...
(Date:11/10/2015)... , Nov. 10, 2015 ... behavioral biometrics that helps to identify and verify ... Signature is considered as the secure and accurate ... identification of a particular individual because each individual,s ... accurate results especially when dynamic signature of an ...
(Date:11/4/2015)... 4, 2015 --> ... published by Transparency Market Research "Home Security Solutions Market - ... 2015 - 2022", the global home security solutions market is expected ... 2022. The market is estimated to expand at a ... to 2022. Rising security needs among customers at homes, ...
Breaking Biology News(10 mins):
(Date:11/24/2015)... , Nov. 24, 2015 /CNW/ - iCo Therapeutics ("iCo" ... reported financial results for the quarter ended September ... in Canadian dollars and presented under International Financial ... States ," said Andrew Rae , ... regarding iCo-008 are not only value enriching for ...
(Date:11/24/2015)... (PRWEB) , ... November 24, 2015 , ... ... event of the year and one of the premier annual events for pharmaceutical ... ran from 8–11 November 2015, where ISPE hosted the largest number of attendees ...
(Date:11/24/2015)... Nov. 24, 2015  Clintrax Global, Inc., a worldwide provider of ... , today announced that the company has set a new quarterly ... quarter on quarter growth posted for Q3 of 2014 to Q3 ... Mexico , with the establishment of an ... --> United Kingdom and ...
(Date:11/24/2015)... ... ... This fall, global software solutions leader SAP and AdVenture Capital brought together ... their BIG ideas to improve health and wellness in their schools. , Now, the ... title of SAP's Teen Innovator, an all-expenses paid trip to Super Bowl 50, and ...
Breaking Biology Technology: