8443
The effect of laydown pattern on scaffold bulk erosion ( weight loss ) was studied by immersion in phosphate-buffered saline ( PBS ) over a 6-month period and measured monthly .
 concept or principle: pattern; engineering feature: scaffold; process parameter: weight; material: PBS
Given options, please tell me the categories of all the listed entity words.Output format is "type1: word1; type2: word2". 
Option: manufacturing standard, machanical property, manufacturing process, material, engineering feature, process parameter, machine or equipment, application, process characterization, enabling technology, biomedical, concept or principle 
Text: {0} 
 Entities: pattern, scaffold, weight, PBS 
Answer:
 concept or principle: pattern; engineering feature: scaffold; process parameter: weight; material: PBS