DOI: 10.5061/dryad.73n5tb38p
title: Spectrophotometric determination of LAP photoinitiator radicalization in ophthalmic applications

description: The incidence of lamellar corneal transplantations is increasing. While a
 human donor cornea could potentially be used for up to two recipients, one
 anterior and one posterior part, it does not change the disparity between
 available donor grafts and patients needing corneal transplants.
 Additionally, donor grafts carry the risk of graft rejection due to
 foreign cellular material and disease transmission. We have investigated
 acellular synthetic graft materials to eliminate these drawbacks using
 hydrogel materials and the extrusion bioprinting process. To create these
 materials with higher moduli, the photocrosslinking process has advantages
 but needs an appropriate crosslinker material. We have shown that we can
 determine the presence of the non-radicalized crosslinker Lithium Phenyl
 (2,4,6-Trimethylbenzoyl) Phosphinate (LAP) with spectrophotometric
 methods, using the crosslinker absorbance characteristics. To show
 non-radicalized LAP, the measurement is done at 372 nm, and the measured
 absorbance level depends on the LAP concentration. This allows for a
 simple evaluation of crosslinked hydrogels to determine any remaining non
 radicalized LAP and with that potential cytotoxic or other effects of this
 crosslinking material and correct this situation if necessary.
description: # Spectrophotometric determination of LAP photoinitiator radicalization in
 ophthalmic applications Dataset DOI:
 [10.5061/dryad.73n5tb38p](10.5061/dryad.73n5tb38p) ## Description of the
 data and file structure Polymers were prepared and photocrosslinked with
 LAP. Optical, mechanical, and chemical testing were performed. All files
 are Microsoft Excel Worksheets. Samples are denoted as X-Y-Z where X is
 the methacrylated silk (SilMA) concentration, Y is the methacrylated
 gelatin (GelMA) concentration, and Z is the LAP crosslinker concentration.
 The Excel worksheets with "Absorbance" in the title are
 absorbance data for polymer samples with varying crosslinking times. The
 number in the title of these sheets is the wavelength. The "Analysis
 of Crosslinking" worksheet contains data from the plate reader with
 one sheet with plots. The three worksheets with "TNBS" in the
 title refer to the TNBS assays used to quantify the degree of
 methacrylation of the scaffolds. The data are the outputs from the plate
 reader in the alignment of the plate, with samples labeled. The final
 worksheet starting with "LAP" also contains outputs from the
 plate reader which are absorbance values. There is a tab with averages
 from the runs as well as plots from those averages. ### Files and
 variables #### File: LAP_datasets_final.zip **Description:** All datasets
 are saved in the compressed folder 'LAP_datasets.zip.' This
 folder contains the following files: Absorbance 372 var XL times.csv,
 Absorbance 450 var XL times.csv, Absorbance 600 var XL times.csv,
 Absorbance 800 var XL times.csv, Analysis of Crosslinking 120 210 300.csv,
 Final ABM TNBS_Modified_ABM 022125_MG.csv, Final SilMA TNBS new Assay
 102124.csv, Final TNBS_LabGelMA_TNBS_MG022825.csv,
 LAP_Radicalization_0.25and1_012425.csv. In all files, samples are denoted
 as X-Y-Z where X is the methacrylated silk (SilMA) concentration, Y is the
 methacrylated gelatin (GelMA) concentration, and Z is the LAP crosslinker
 concentration. All data are raw data unless otherwise noted in the
 document. There is a description of each of these datasets below: ###
 Absorbance Data Description: These data are derived from plate reader
 measurements at wavelengths of 372 nm, 450 nm, 600 nm, and 800 nm. The
 values are unitless measures of absorbance. Files: Absorbance 372 var XL
 times.csv, Absorbance 450 var XL times.csv, Absorbance 600 var XL
 times.csv, Absorbance 800 var XL times.csv Variables: * XL time:
 crosslinking time in seconds (s) * DI water: deionized water control
 samples Files: Analysis of Crosslinking 120 210 300.csv Variables: *
 Wavelength: light wavelength in nm * DI water tot av: total average of
 deionized water control samples * Sample notation: X-Y-Z As (time in
 seconds) (e.g., SilMa-GelMa-LAP 4-4-0.25 120s)
 Files: LAP_Radicalization_0.25and1_012425.csv Variables: * Wavelength:
 light wavelength in nm * DI water: deionized water control samples *
 Sample notation: LAP 0.25% represents 0.25% crosslinker concentration, LAP
 1.0% represents 1.0% crosslinker concentration ### TNBS Assay Data
 Description: These data are derived from plate reader measurements of
 96-well plates with samples and reagents used for the TNBS assay. See
 detailed methods in publication. The values are unitless measures of
 absorbance. The key for the well plate samples is listed in the sheet
 (e.g., A123 blank means cells A1, A2, A3 were blank). Concentrations are
 calculated in the file based on the standard curve. Control groups were
 Silk_Fibroin and Gelatin (unmodified - not methacrylated). Files: Final
 ABM TNBS_Modified_ABM 022125_MG.csv, Final SilMA TNBS new Assay
 102124.csv, Final TNBS_LabGelMA_TNBS_MG022825.csv Variables: * Abs:
 absorbance (unitless) * blank: reaction buffer only plus TNBS reagent *
 DS: degree of substitution * A-H: well plate rows * 1-12: well plate
 columns * Cntrl: control ## Code/software None ## Access information Other
 publicly accessible locations of the data: * N/A Data was derived from the
 following sources: * Swindle-Reilly Lab, Chandler Lab, The Ohio State
 University