RSC Advances Blog

Transfection is the process of introducing genetic material, typically DNA, into mammalian cells. This technique has proven indispensable in understanding signaling networks that govern cellular function. To better understand the function of a given protein, molecular biologists routinely transfect cells with DNA (i.e. recombinant DNA). This enters cells in culture and subsequently encodes the specific protein under study. The recombinant DNA is combined with a transfection reagent, typically Lipofectamine, to facilitate its entry into cells.

A study conducted by Neuhaus and colleagues, at the Inorganic Chemistry and Center for Nanointegration (CeNIDE) in Germany, utilizes calcium phosphate nanoparticles (CPNPs) as vehicles to deliver recombinant DNA into cells. CPNPs have previously been shown to spontaneously bind DNA, thus supporting the notion that they could be used as transfection agents. The approach requires that CPNPs first be mixed with a buffer containing recombinant DNA before being added to cultures containing actively growing mammalian cells.

Despite its simplistic approach, the transfection process in general has a few technical limitations. First, not all cells in culture uptake the recombinant DNA. This leads to reduced transfection efficiency. Second, the transfection efficiency is strongly influenced by the cell type (i.e. distinct cell forms within a species). And third, cells interpret recombinant DNA as ‘foreign’ genetic material and trigger alarms which culminate in cell death.

Images demonstrating the uptake of green flourescent nanoparticles by different cell types

To better assess the utility of CPNPs as transfection agents, the study’s authors first transfected ten different cell types with DNA. The DNA in their study encoded a protein that fluoresces green when excited at a specific wavelength. Using Lipofectamine as a comparator reagent, the study assessed the transfection efficiency of CPNPs by measuring the proportion of cells that glowed green under a fluorescent microscope. The study also highlighted the differences in transfection efficiencies between different cell types. The authors propose that CPNPs represent promising candidates as transfection agents and therefore warrant further study.

Clinical trials utilizing nucleotide-based targeted therapies for multiple human diseases are on the rise. CPNPs may represent the new breed of nucleotide-based drug delivery agents in the years to come.

Read the full article here:

Nanoparticles as transfection reagents: a comprehensive study with ten different cell lines
Bernhard Neuhaus,  Benjamin Tosun, Olga Rotan, Annika Frede, Astrid M. Westendorf and Matthias Epple
RSC Adv., 2016,6, 18102-18112
DOI: 10.1039/C5RA25333K

Turmeric, a spice commonly used in curries, contains a natural polyphenol called curcumin, which has been revealed as a promising anti-cancer therapeutic.

Tautomeric forms of curcumin and nanoparticle drug delivery systems

The undesirable properties and side effects of current anti-cancer therapeutics have inspired scientists to search for a natural remedy which may be better tolerated.  Curcumin has been demonstrated to inhibit cancer cell survival and to induce apoptosis without promoting the development of side effects.

Studies comparing the incidences of cancer in India and the West revealed that there was a lower risk of cancer in India. It is proposed that a major contribution to these statistics could be the increased intake of plant derivatives, such as curcumin, into the diet. In Asia, turmeric has been used for its medicinal properties for more than two thousand years!

In the 1800s scientists were able to isolate the curcumin molecule, but the structure wasn’t elucidated until 1910 – it is the structure which is responsible for its unique physiochemical and biological properties:

• Often used as a dye due to its vibrant colour.
• Increases the thermal stability of collagen, used for dermal wound healing.
• Stability is maintained at room temperature allowing it to be used for medicinal purposes.

Traditional medicine has used curcumin to treat several conditions including inflammation, respiratory infections and blood clotting, but there is a rapidly growing interest in its effects on cancer.

Curcumin has yet to be licenced as a drug, possibly due to its susceptibility to rapid degradation in a wide range of environments and its sensitivity to pH and light. Under certain conditions curcumin becomes unstable and degrades, yielding other compounds. As many drug delivery systems tend to stabilize curcumin it needs to be determined whether it is curcumin itself or its degradation products that provided the biological activities observed.

To find out more about the chemical properties, bioactivity and approaches to cancer cell delivery of curcumin, read the full review by clicking the link.

Curcumin, a promising anti-cancer therapeutic: a review of its chemical properties, bioactivity and approaches to cancer cell delivery
Melessa Salem, Sohrab Rohani and Elizabeth Gillies
DOI: 10.1039/C3RA46396F

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Cancer is a devastating disease which kills millions of people each year. Although treatment for cancer has come a long way, current treatment relies on using toxic chemotherapeutic drugs, which can also kill healthy cells causing terrible side effects for patients. Nanotechnology and nanvectors have emerged as a new strategy in cancer treatment, as they protect the drugs from premature degradation, and improve the pharmacodynamics of the drugs. However, very few nanovector-based drugs are currently available.

In this work, Sudipta Basu and co-workers, from Pune, India, have developed a novel nanovector from lithocholic acid (LA), a naturally occuring bile acid. The nanoparticles can self-assemble to develop supramolecular nanostructures, and are under 200 nm in size which is beneficial for targeting tumours by enhanced permeability and retention. The nanoparticles can hold the clinically approved cytotoxic drugs doxorubicin, paclitaxel and PI103, and release the active drugs in a controlled manner at pH 5.5. They can also be decorated with antibodies, aptamers or cell surface receptor targeting peptides, for tissue specific delivery of cytotoxic drugs.

Read the full article to find out more. It’s free to access for 4 weeks!

Novel self-assembled lithocholic acid nanoparticles for drug delivery in cancer, Sumersing Patil, Sohan Patil, Suhas Gawali, Shrikant Shende, Shraddha Jadhav and Sudipta Basu, RSC Advances, 2013, DOI: 10.1039/c3ra42994f

Sara Coles is a guest web-writer for RSC Advances. She currently works for Johnson Matthey in Royston, UK.

Jiahong Li and colleagues at Chengdu Institute of Organic Chemistry in China have prepared water-soluble ligands to allow transition metal catalysed asymmetric transfer hydrogenation (ATH) of aromatic ketones, especially aromatic ketones with a bromine group in the alpha position. They produced the expected alcholos with ees up to 96% and the catalyst could be reused at least 21 times.

The reactions were carried out in the presence of cationic surfactant CTAB (cetyltrimethylammonium bromide). Of the three catalytic metals tested, ruthenium, iridium and rhodium, they report that the best results were obtained using ruthenium.

Products synthesised using the novel catalyst system included key pharmaceutical intermediates for anti-asthma drugs, terbutaline and salbutamol.

Read more about the experimental work in RSC Advances:

Surfactant-accelerated asymmetric transfer hydrogenation with recyclable water-soluble catalyst in aqueous media, Jiahong Li, Xuefeng Li, Yaping Ma, Jiashou Wu, Fei Wang, Jing Xiang, Jin Zhu, Qiwei Wang and Jingen Deng, RSC Adv., 2013, 3, 1825

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