Fluorescent Composite Scaffolds Made of Nanodiamonds/Polycaprolactone

Polycaprolactone (PCL) has been widely studied for biological applications. Biodegradable PCL fibrous scaffold can work as an appropriate substrate for tissue regeneration. In this letter, fluorescent nanodiamonds (FNDs) were prepared after surface passivation with octadecylamine. The FNDs were then mixed with PCL polymer and subsequently electrospun into FNDs/PCL fibrous scaffolds. The obtained scaffolds not only exhibited photoluminescence, but also showed reinforced mechanical strength. Toxicity study indicated FNDs/PCL scaffolds were nontoxic. This biocompatible fluorescent composite fibrous scaffold can support in vitro cell growth and also has the potential to act as an optical probe for tissue engineering application in vitro and in vivo

A new method using Raman spectroscopy for in vivo targeted brain cancer tissue biopsy

Abstract Modern cancer diagnosis requires histological, molecular, and genomic tumor analyses. Tumor sampling is often achieved using a targeted needle biopsy approach. Targeting errors and cancer heterogeneity causing inaccurate sampling are important limitations of this blind technique leading to non-diagnostic or poor quality samples, and the need for repeated biopsies pose elevated patient risk. An optical technology that can analyze the molecular nature of the tissue prior to harvesting could improve cancer targeting and mitigate patient risk. Here we report on the design, development, and validation of an in situ intraoperative, label-free, cancer detection system based on high wavenumber Raman spectroscopy. This optical detection device was engineered into a commercially available biopsy system allowing tumor analysis prior to tissue harvesting without disrupting workflow. Using a dual validation approach we show that high wavenumber Raman spectroscopy can detect human dense cancer with >60% cancer cells in situ during surgery with a sensitivity and specificity of 80% and 90%, respectively. We also demonstrate for the first time the use of this system in a swine brain biopsy model. These studies set the stage for the clinical translation of this optical molecular imaging method for high yield and safe targeted biopsy

Media 1: Characterization of a Raman spectroscopy probe system for intraoperative brain tissue classification

Originally published in Biomedical Optics Express on 01 July 2015 (boe-6-7-2380

In situ brain tumor detection using a Raman spectroscopy system—results of a multicenter study

Abstract Safe and effective brain tumor surgery aims to remove tumor tissue, not non-tumoral brain. This is a challenge since tumor cells are often not visually distinguishable from peritumoral brain during surgery. To address this, we conducted a multicenter study testing whether the Sentry System could distinguish the three most common types of brain tumors from brain tissue in a label-free manner. The Sentry System is a new real time, in situ brain tumor detection device that merges Raman spectroscopy with machine learning tissue classifiers. Nine hundred and seventy-six in situ spectroscopy measurements and colocalized tissue specimens were acquired from 67 patients undergoing surgery for glioblastoma, brain metastases, or meningioma to assess tumor classification. The device achieved diagnostic accuracies of 91% for glioblastoma, 97% for brain metastases, and 96% for meningiomas. These data show that the Sentry System discriminated tumor containing tissue from non-tumoral brain in real time and prior to resection

Combined fiber probe for fluorescence lifetime and Raman spectroscopy

In this contribution we present a dual modality fiber optic probe combining fluorescence lifetime imaging (FLIm) and Raman spectroscopy for in vivo endoscopic applications. The presented multi-spectroscopy probe enables efficient excitation and collection of fluorescence lifetime signals for FLIm in the UV/visible wavelength region, as well as of Raman spectra in the near-IR for simultaneous Raman/FLIm imaging. The probe was characterized in terms of its lateral resolution and distance dependency of the Raman and FLIm signals. In addition, the feasibility of the probe for in vivo FLIm and Raman spectral characterization of tissue was demonstrated