• UV-Vis Spectroscopy: Ultraviolet-vis spectroscopy is a useful technique for quantitative estimation of species that absorb in the UV-visible region.  This is also useful for the estimation of impurities that absorb in the UV-vis region.

• High Performance Liquid Chromatography (HPLC): This technique is used for purity analysis of small molecules (e.g. monomers and precursors), analysis of degradation products of polymeric biomaterials, and analysis of drug released from various drug-containing matrices. A new Waters Associates Empower HPLC acquired this year is fully automated and has a capacity of analyzing 120 samples.


• Karl-Fischer Coulometer Titrator: This equipment acquired by the center this year accurately measures low quantities of water present in chemical compounds and polymers. It is often very difficult to remove trace amounts of water from these materials. A knowledge of the quantity of trace water aids in polycarbonate synthesis by phosgenation where the moisture should be compensated by adding required excess of phosgen.
  

• Gel Permeation Chromatography (GPC): Gel permeation chromatography (GPC) is fundamental to the characterization of polymeric biomaterials, since molecular weight, Mw distribution, and polydispersity are important parameters that affect the properties of the polymeric biomaterials.  This is also used to determine the degradation rate of polymers under in vitro and in vivo conditions.

• Viscotek’s GPC with Triple Detection system: Combination of refractive index (RI), Light scattering, and Viscometric detectors in this GPC system, also acquired this year, one can measure absolute molecular weight, hydrodynamic volume, radius of gyration, and intrinsic viscosity in a single run lasting 30 min. In addition, it also has a UV-detector, which in combination with the RI detector can determine the composition of block copolymers.

• Differential Scanning Calorimetry (DSC):  Differential scanning calorimetry is mainly used for the determination of glass transition temperature (Tg) and melting temperature (Tm) of polymers. DSC is also used routinely to determine the purity of monomers and other small molecules.

• Mechanical Tester (MTS):  The Syntec 5/D mechanical tester with environmental chamber is routinely used for testing films, fibers, cylindrical pins and porous scaffolds. These equipment enables measurement of mechanical properties of biomaterials (porous scaffolds, cylindrical pins, thin fibers, films, etc) under physiological conditions.

• Quartz Crystal Microbalance with Dissipation:  Real time kinetics of adsorption phenomena can be detected with the quartz crystal microbalance with dissipation monitoring (QCM-D, Q-sense, Gothenburg, Sweden). A quartz crystal sensor is made to oscillate by applying an AC-field at a frequency close to the resonance frequency of the quartz crystal, which is usually in the MHz range.  The strength and the uniqueness of this newly developed technique is the simultaneous monitoring of the changes in the resonant frequency (and in several overtones) and in the dissipation induced by the deposition of a film or a viscoelastic material (polymer film or protein layer) on the crystal sensor. The new high-throughput E4 instrument measures 4 samples simultaneously where frequency and dissipation changes are modeled applying a Voigt – based model allowing for the determination of film properties such as thickness and viscoelastic properties.


• Thermogravimetric Analyzer (TGA):  Thermogravimetric analyzer has two important applications-determination of volatile components in a material and the determination of the decomposition temperature.  The microbalance of the TGA can very accurately determine the weight of a test material as a function of temperature.

• Liquid Chromatography Mass Spectrometry: The Finnigan LC-MS is a modern (delivered in 2000) quadrapole MS/MS instrument with a mass detection range from 50 to 2000 atomic mass units. The system utilizes ion-trap technologies permitting the isolation of low level ions for analysis. The system also has attachments for sample introduction via HPLC, electrospray or atmospheric pressure chemical ionization (APCI). In addition to the full scan mode, the instrument can operate in selected ion monitoring, selected reaction monitoring, and narrow mass range high resolution modes. The system has a sophisticated computer system for instrument control and data collection, with a spectral reference library.

• DelsaNano S - Submicron particle size analyzer (0.6 nm - 7 um): Dynamic light scattering technique is used to determine the size distribution profile of small particles in suspension (chemistry) or polymers in solution.  This analysis is used in medical, biological research and materials science applications, and is also known as photon correlation spectroscopy or quasi-electron light scattering.

• The Leica CM1850 cryostat is a sectioning device with an optimized cooling system, rapid specimen freezing and smooth specimen orientation for the high-quality sectioning demanded in routine histology and clinical pathology.

• X-Ray Diffraction (XRD) is a powerful non-destructive technique used to analyze and characterize different materials from fluids, powders, films, etc. It can provide detailed information about chemical composition, structure, and physical properties. XRD works by hitting the sample with the X-ray beam and an analysis of the angle, wavelength or energy (Rigaku) of the incident and scattered beams.

• Scanning Electron Microscopy (SEM): An Amray 1830I (20 kV) SEM at Rutgers University is available to image and characterize morphology.  The surface is scanned in a raster pattern with a high energy beam of electrons. This imaging technique is used to observe sub-micron features of fabricated medical device prototypes.