New Nanoparticle Design Aids in Improved Drug Delivery to Cancer Cells
등록일 2019년 01월 07일 일요일
수정일 2017년 11월 05일 일요일

Photo by: nobeastsofierce via Shutterstock

Researchers at the University of New South Wales found a way to control the shape of polymersomes, using an advanced tool that could deliver toxic drugs to tumor cells.Polymersomes are artificial vessels with tiny hollow spheres that contain a solution.These nanoparticles are similar to liposomes but are significantly stable and more flexible.However, the full potential of the nanoparticles is obstructed by the difficulty of controlling their shape.

In the study, the researchers used a new chemical design for polymersomes to control its shape.The design involves adding a non-water soluble perylene polymer group to the polymersomes' membrane.While changing the volume of water in the solvent, it adjusts the shape and size of the polymersomes.

"It's a straightforward but elegant solution which we feel has great potential for making a wide range of complex polymer structures inspired by nature," said Martina Stenzel, a professor at Scientia.

The breakthrough of their study is a precedent for creating smart polymers that adapt to different conditions by changing their shape.The polymersomes can assume various shapes, such as spherical, tubular, and ellipsoidal.Polymersomes that are shaped more naturally like ellipsoids and tubes can easily penetrate tumors than spherical models, according to Pall Thordarson, senior author of the study and a professor at UNSW School of Chemistry.

Different Shapes of Cells

There are at least 200 different types of cells in the human body and inside these cells are at least 20 various organelles, tiny structures in cells, and a nucleus that acts as the command center.These cells have different shapes like columnar that appears as tall cells and squamous that looks thin, flat, and scaly ones.

Prokaryotic cells like bacteria have simpler cell structures than animal or plant cells.Bacteria also lack chlorophyll, nucleus or membrane-bound organelles.Common shapes of bacteria are the bacillus or rod, the coccus or sphere, and the spiral or vibrio.Depending on the structure of the bacteria, it can have a specific arrangement when viewed under a microscope.It can be a diplo or a set of paired bacterial cells, grape-like clusters or staphylo, or chains called strepto.

Viruses are agents that infect any cells and have sizes measured in nanometers.The core of a virus is made up of nucleic acids that make up the genetic information in RNA or DNA form.

1.The icosahedron or sphere is the shape of the poliovirus, adenovirus, and rhinovirus, the common cold.

2.The envelope is an icosahedron or helix surrounded by a lipid membrane.Influenza viruses, hepatitis C, and HIV are all envelop-shaped viruses.

3.The complex is a combined shape of icosahedron and helix with or without a head-tail morph.Poxviruses that causes smallpox is a complex-shaped virus.

4.The helix is a tube with a capsid and a hollow central area made up of proteins.The tobacco mosaic virus has a helical symmetry.

Targeted Treatment for Cancer

The targeted treatment for cancer uses drugs that are designed to inhibit the growth and spread of cancer cells, instead of destroying and killing then, as usually done by chemotherapy.This type of cancer therapy targets specific molecules related to the cancer's ability to multiply.Targeted molecules are genes, proteins or parts of cancer cells.

- Monoclonal antibodies are drugs that block a specific target on the outside of cancer cells, including the area where tumors are located.The antibodies can also be directed to deliver toxic chemicals to tumors to aid in the effectiveness of chemical or radiation therapy.

- Small-molecule drugs block the reproduction process of cancer cells.Angiogenesis inhibitors disrupt the ability of tissues around tumors to make new blood vessels.By doing this, tumors starve because of the inability to receive nutrients from blood vessels.

- Hormone therapy uses drugs that prevent the body to produce certain hormones.Some tumors respond to hormones and use it to grow and spread.

- Apoptosis inducers are drugs designed to force cancer cells to undergo a controlled cell death process called apoptosis.

- Immunotherapies trigger the immune system to combat and destroy cancer cells.

Potential Side Effects

Use of targeted therapies has potential side effects, such as diarrhea, hepatitis, and elevated liver enzymes.Other possible side effects include skin problems, issues with blood clotting and wound healing, high blood pressure, and gastrointestinal perforation, or piercing of the stomach or intestinal lining, according to the National Cancer Institute.

Examples of Applied Targeted Treatment

- About 20 to 25 percent of all breast cancer patients have elevated human epidermal growth factor receptor 2 protein.Targeted therapy is used for cases like this to inhibit tumor growth.

- A protein called the epidermal growth factor receptor is often found in colorectal cancer patients.Drugs that block EGFR and the vascular endothelial growth factor may stop tumor growth and prevent new blood vessels to grow.

- Lung cancer may be treated with both angiogenesis and EGFR inhibitors to stop the disease.

- About 50 percent of melanoma cases have been presented with BRAF gene mutation.There are several BRAF inhibitors approved by the US Food and Drug Administration.

There are several targeted therapies that are available for other types of cancer including cancer of the brain, bladder, cervical, liver, pancreas, and prostate.

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