TOF-Secondary Ion Mass Spectrometry Imaging of Polymeric Scaffolds with Surrounding Tissue after in Vivo Implantation

Abstract

Supramolecular polymeric materials are of increasing interest for the use as drug delivery carriers. A thorough insight in the biocompatibility and the degradation of these materials in vivo are of fundamental importance to further their development and application in medical practice. Molecular imaging techniques are powerful tools that enable the elucidation of molecular distributions in and around such polymer implants. A supramolecular polymeric hydrogel was implanted under the renal capsule to study its biocompatibility with TOF-SIMS. This results in a molecular cartography of the polymer implant combined with the cellular signature of the implantation environment. In this experiment, molecular signals are observed from cells that are involved in the biological response to the implant, e.g., macrophages. These molecular signatures are compared with macrophage standards cultured in different polarization environments. On the basis of this comparison, information can be acquired on the various macrophage differentiations that are connected to different stages in the foreign body response. Mass spectrometric imaging techniques offer the opportunity to visualize different histological phenomena in a single experiment without the need for specific immunohistochemical markers. Cellular infiltration into the polymer is visualized, offering a clear view on both biological and polymer features in a single imaging experiment.

Secondary ion mass spectrometry and Raman spectroscopy for tissue engineering applications

“…Calibration spectra of cells of known phenotype has also enabled identifying cell types that are studied for tissue engineering applications [41,43]. The phenotypes of macrophages around a hydrogel implant have been tentatively identified by visually comparing their spectra to TOF-SIMS data from the macrophage subtypes involved in biological response to foreign material [43].…”

“…The phenotypes of macrophages around a hydrogel implant have been tentatively identified by visually comparing their spectra to TOF-SIMS data from the macrophage subtypes involved in biological response to foreign material [43]. We have successfully identified the differentiation states of individual, primary hematopoietic cells from three distinct states of B cell lymphopoiesis with a PLS-DA model of calibration TOF-SIMS data from hematopoietic stem and progenitor cells (HSPCs), common lymphoid progenitors (CLPs), and B cells [41].…”

Analytical strategies for studying stem cell metabolism

“…Several approaches are being developed, including nano-electrospray ionization, microfluidic chips and sample arrays for monodispersed sample droplets as sample sources for MS data acquisition (Urban et al, 2010). Detection of single cell metabolites is also a focus of emerging imaging mass spectrometry, which may achieve spatial resolution at the micron level (Secondary Ion Mass Spectrometry, SIMS) (Klerk et al, 2010). While this technology remains qualitative, it provides additional data relevant for molecular phenotyping in a variety of experi-mental conditions.…”

A vision for better health: Mass spectrometry imaging for clinical diagnostics

“…Biodegradable polymers are of high interest in the medical field because of their potential applications in the field of tissue engineering and as drug delivery carriers [105]. Supramolecular polymers have gained much interest as potential drug delivery carriers because of their compatibility with weak water soluble compounds and their potential for controlled drug release [19,115-121].…”