Photostabilized compositions and a method for stabilizing photosensitive components
Photostabilized compositions may include a water-soluble tyrosine-containing compound with a molecular weight of below 1 kDa and at least one photosensitive component. A method for stabilizing one or more photosensitive components may include the addition of a tyrosine-containing dipeptide with the one or more photosensitive components. The water-soluble tyrosine-comprising compound may be present at a concentration of at least 0.5 mM. The composition may be a culture medium.
1 . A method for stabilizing a photosensitive composition, the method comprising: combining Ala-Tyr or Gly-Tyr, at a concentration in a range of from 0.5 to 20 mM, with a photosensitive composition comprising tryptophan in at least 2.5 mM, thereby stabilizing the photosensitive composition against brown coloration, wherein the photosensitive composition is an aqueous culture medium comprising a carbohydrate, a further free amino acid, an inorganic salt, a buffering agent, an/or a vitamin, wherein a molar ratio of the Ala-Tyr or Gly-Tyr to the tryptophan is in a range of from 0.2:1 to 8:1.
2 . The method of claim 1 , further comprising:
combining a cysteine derivative with the photosensitive composition.
3 . The method of claim 1 , wherein the photosensitive composition comprises cultured cells and is formed as a cell culture medium.
4 . The method of claim 1 , wherein the combining employs the Gly-Tyr.
5 . The method of claim 1 , wherein the combining employs the Ala-Tyr.
6 . The method of claim 3 , wherein the cultured cells are CHO cells, COS cells, VERO cells, BHK cells, HEK cells, HELA cells, AE-1 cells, NS0 cells, insect cells, algae cells, fibroblast cells, muscle cells, nerve cells, stem cells, skin cells, endothelial cells, immune cells, or hybridoma cells.
7 . The method of claim 1 , wherein the concentration of the Ala-Tyr or Gly-Tyr in the combining is in a range of from 0.5 to 10 mM.
8 . The method of claim 1 , wherein the aqueous culture medium comprises His, Ile, Leu, Lys, Met, Phe, Thr, Tyr, and Val.
9 . The method of claim 1 , wherein the free amino acid of the aqueous culture medium comprises glutamine at a higher concentration than other amino acids.
10 . The method of claim 1 , wherein the aqueous culture medium comprises glutamine, as the free amino acid, in a concentration of from 2.5 to 8 mM, and
wherein a molar ratio of the Ala-Tyr or Gly-Tyr to the tryptophan is in a range of from 0.2:1 to 4:1.
11 . The method of claim 1 , wherein the aqueous culture medium is in 2 to 100-fold concentrated form.
12 . The method of claim 1 , wherein the combining reduces the brown coloration to no more than 77.8% of an absorbance in UV-vis at 330 nm of an otherwise identical aqueous culture medium without the Ala-Tyr or Gly-Tyr.
13 . The method of claim 1 , wherein the combining employs both the Ala-Tyr and the Gly-Tyr.
14 . The method of claim 1 , further comprising:
allowing the photosensitive composition to be exposed to daylight.
15 . The method of claim 1 , wherein the aqueous culture medium further comprises riboflavin.
16 . The method of claim 1 , wherein the aqueous culture medium further comprises a hexose.
17 . The method of claim 1 , wherein the combining is carried out for duration in a range of from 7 to 14 days.
18 . The method of claim 1 , wherein the combining is carried out for 7 days.
19 . The method of claim 1 , wherein the combining is carried out for 14 days.