Special Issues-06-01-2011

Raman spectroscopy (weak H2O Raman scattering) has been a tool of choice for investigating aqueous lipid suspensions. Recently, there has been interest in supported lipid bilayers (SLBs), where lipids are believed to have fluidities similar to those of free vesicles, and thus have been investigated for applications such as sensors and drug delivery vehicles. Here, Raman spectra of two lipid SLBs on SiO2 nanoparticles were obtained. With decreasing nanoparticle size, or for the same nanoparticle size and longer alkyl chain length, the lipids became increasingly interdigitated compared with the normal bilayer structure.

Raman spectroscopy offers a rapid, simple, and nondestructive technique for the identification of counterfeit medicines. The advantages of handheld Raman spectroscopy are that it is easy to use by unskilled personnel and it can identify a test pharmaceutical product on the spot, whether the product is in solid or liquid form. However, these instruments can operate only in reflection mode, and the Raman activity of a sample is often masked by fluorescent species in the sample, especially when the analysis is made in reflection mode. The objective of this work was to compare the use of a handheld and laboratory-based Raman instruments for authentication of pharmaceutical products obtained from the world market.

In this article, we present a method that provides prompt detection of the presence of cancer cells inside the 2-mm margin of tissue surrounding the tumor after excision using spatially offset Raman spectroscopy (SORS). SORS was developed to detect subtle changes in soft tissue spectra in the 100–2000 ?m range and tested on excised breast tissues. The results display a very high specificity and sensitivity (100% and 95%, respectively) of classification between positive and negative tumor margins. SORS is a clinically feasible method, suitable for the real-time, intraoperative assessment of tumor margins at the micrometer level.