boron nitride (cubic)

Additional toxicological data

Administrative data

Endpoint:

additional toxicological information

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2009

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP conform study following guideline 90/385/EWG, 93/42/EWG and DIN EN ISO/IEC 17025 for testing of medical devices.

Materials and methods

Type of study / information:

This ln vitro method analyses the cytotoxic potential of the test item. The test is carried out using the mouse cell line L929 cultured with differentconcentrations of an extract of the test item. The vitality of the cells or potential cytotoxic effects of the extract are registered via the protein content of the cell culture as compared to the controls.

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: ISO 10993-1 "Evaluation and testing within a risk management process"

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: ISO 10993-5 "Tests for in vitro cytotoxicity"

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

other: ISO 10993-12 "Sample preparation and reference materials"

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Results and discussion

Any other information on results incl. tables

Test item: Synthetic cubic Boron Nitride Grade 2 (2 micron) Powder

	Rel. Protein content (A550) (a)
	1	2	3	x	+	s	Growth inhibition in %
Blank	0.111	0.111	0.110	0.111	+	0.000
Positive control (b)	0.199	0.213	0.227	0.213	+	0.011	88
Negative control (c)	0.870	0.874	0.812	0.852	+	0.028	14
Solvent control
100 % v/v	0.956	0.956	0.996	0.969	+	0.019	0
66.7 % v/v	1.024	1.035	1.037	1.032	+	0.006	0
44.4 % v/v	1.048	1.058	0.994	1.033	+	0.028	0
29.6 % v/v	0.905	0.913	0.935	0.918	+	0.013	0
19.8 % v/v	1.060	1.018	0.993	1.024	+	0.028	0
13.2 % v/v	1.000	1.013	0.978	0.997	+	0.014	0
Test extract (d)
100 % v/v	0.800	0.810	0.853	0.821	+	0.023	17
66.7 % v/v	0.923	0.959	0.941	0.941	+	0.015	10
44.4 % v/v	0.993	1.037	1.039	1.023	+	0.021	1
29.6 % v/v	0.903	0.938	0.917	0.919	+	0.014	0
19.8 % v/v	1.048	1.030	1.050	1.043	+	0.009	0
13.2 % v/v	1.022	0.987	1.020	1.010	+	0.016	0

(a) 3 parallel cultures, mean + standard deviation

(b)5% DMSO in DMEM l0% FCS

(c) PE material extracted in DMEM l0% FCS

(d) The test item was extracted under agitation in DMEM l0% FCS for 24 + 2 h at 37 + 1°C and the extract was cultured for 68- 72 h with L929 cells at a final weight/volume ratio of 0.2 g test item / mL culture

The controls confirmed the validity of the study. Cell growth of the positive cultures was inhibited by 88%. The extract of the negative control did not show a relevant inhibition of cell growth (14%).

Applicant's summary and conclusion

Conclusions:

In this study under the given conditions no leachable substances were released in cytotoxic concentrations from the test item.

Executive summary:

In the present study the cytotoxic effects of Synthetic cubic Boron Nitride Grade 2 (2 micron) Powder were analysed. Hereby, the test item was extracted under agitation for 24 t 2 h with cell culture medium and the extract was incubated with L929 cells for 68 - 72 h. The protein content of the individual cultures was then analysed as a measure for cytotoxicity and compared to those of the controls.

In this study under the given conditions no leachable materials were released in cytotoxic concentrations from the test item.