A density-functional microscopic model for soft tissues (STmod) is presented. The model was based on a prototype molecular structure from experimentally resolved type I collagen peptide residues and water clusters treated in periodic boundary conditions. We obtained the optimized geometry, binding and coupling energies, dipole moments, and vibrational frequencies. The results concerning the stability of the confined water clusters, the water-water, and water-collagen interactions were successfully correlated to some important experimental trends of normal and inflammatory tissues.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Univ Fed ABC, BR-09210580 Santo Andre, SP, BrazilUniv Estadual Paulista, UNESP, Inst Fis Teor, BR-01140070 Sao Paulo, SP, BrazilDublin Inst Technol, FOCAS Inst, Dublin 8, IrelandUniv Estadual Paulista, UNESP, Inst Ciencia &Tecnol, Dept Biociencias Diagnost Bucal, BR-12245000 Sao Jose Dos Campos, SP, BrazilUniv Estadual Paulista, Instituto de Física Teórica (IFT), BR-01140070 Sao Paulo, SP, BrazilUniv Estadual Paulista, UNESP, Inst Ciencia &Tecnol, Dept Biociencias Diagnost Bucal, BR-12245000 Sao Jose Dos Campos, SP, Brazil