Particulate systems which can be engineered to target specifically certain cells or tissues are another promising alternative.
Attention is increasingly focusing on fine particles, or particulate matter, which can be carried deep into the lungs, causing inflammation and increasing the risk of heart attack.
The cross-section observation (Fig. 1f) does not show the presence of a continuous superficial deposition; on the other hand, the surface discontinuities and micro-fissures appear partly filled by soil dust and particulate matter which can be responsible for the observed colour alteration.
Amphiphilic cationic block copolymers consisting of poly ethylene glycol), poly(ε-caprolactone) and poly ethylene imine) spontaneously assemble to nano-sized particulate carriers, which can be utilised for complexation of nucleic acids (small-interfering RNA), representing a multifunctional vector system, designed for drug and gene delivery.
A phase I clinical trial was conducted to compare Lymphoseek with filtered 99mTc-sulfur colloid (a particulate complex which can be taken up by the reticuloendothelial system) for melanoma sentinel lymph node detection in patients (Wallace et al 2007).
Our latest development, the CULTEX® RFS module, is characterized by a radial distribution of the test atmosphere from one sampling point to the cells, resulting in a homogeneous deposition of particulate matter on the cells which can be calculated according to a simplified model distinguishing between sedimentation, differentiation and electrical deposition (Fig. S 1 in the ESM).
Particulate is extracted followed by absorbance measurements which can be converted into concentrations using a PM standard curve.
The current study has demonstrated that tobacco cigarette particulate matter contains surface bound free radicals which can be detected in situ during cigarette smoking.
In vivo testing of these particulate forms can be limited by experimental constraints, which can be addressed using in vitro tests.
The smog is particularly dangerous because of its high concentration of particulates measuring less than 2.5 microns (PM2.5) in diameter, which can be inhaled deeply into the lungs and absorbed into the bloodstream.
