Lethal photosensitisation of bacteria using a tin chlorin e6–glutathione–gold nanoparticle conjugate

Continuous release of gentamicin from gold nanocarriers

“…3 ) regardless of the capping agent (data not shown); the diameter was 5.2 ± 1.1 nm and 7.8 ± 1.2 for glutathione and l -cysteine capped nanoparticles respectively; in both cases the conjugation did not affect the gold core size of the nanoparticles as expected and also found in previous gold conjugates. 11 These two results are in agreement as larger nanoparticles exhibit absorbance peaks at progressively greater wavelength (from red to purple to dark violet).…”

“…7 – 9 Their synthesis is generally performed through the reduction of Au 3+ using inorganic agents or through biogenic approaches. Capping agents such as: tiopronin, 10 glutathione 11 and l -cysteine 12 have also been employed exploiting the thiol affinity toward gold; moreover they provide stability to the particles and allow further grafting of molecules to the gold carrier.…”

Biogenic synthesis of antimicrobial silver nanoparticles capped with l-cysteine

“…Depending on the properties of this capping agent, the characteristics (geometry and solubility) of the nanoparticles can be controlled. The choice of capping agent must be directed by the characteristics and application of the intended nanoparticles; for biological applications, polypeptides (gluthatione) [21,45,46], tiopronin [10,33] and aminoacids have been previously employed [31,45]. The common feature of these compounds is the presence of sulphur whose strong affinity for Ag results in coverage of the nanoparticles and provides stability during nanoparticles ripening.…”

Nanoparticles in Photodynamic Therapy

“…A definite increase in singlet oxygen quantum yield was observed, which can probably be attributed to an effect similar to metal enhanced fluorescence [55]. Again, different photosensitisers such as TBO [56], porphyrins [57], chlorins [58] and others have been tested. An attractive feature of this approach is that gold nanoparticles are non-toxic and already used in therapy.…”

“…This problem might be solved in the future by using less toxic base materials such as InP or CuInS 2 . Finally, the two most promising approaches were TBO [56] porphyrins [57] Sn chlorin e6 [58] photosensitiser-doped silica nanoparticles and gold nanoparticle/photosensitiser conjugates. Both systems showed very promising results and the underlying nanoparticles have already clinical approval for other applications.…”