Biopolymeric gelation is a field of great theoretical, practical and biological interest. The gel state of matter is reached through the topological phase transition of intermolecular cross-link percolation. This occurs when a threshold value of polymer concentration is reached depending on temperature and bond energy. It has been recently shown that formation of physical gels can occur even at concentration well below the random cross-linking threshold. In these conditions, solute-solute correlation is provided by the thermodynamic phase transition of demixing. Spontaneous concentration fluctuations generate lower and higher than average concentration regions. Depending on the total polymer concentration, high-density domains, where cross-linking is favored, may remain mutually disconnected or assembly in a percolative structure. In the first case, here discussed, gelation occurs only on mesoscopic scale. Dependence of size and shape of gel aggregates upon quenching temperature and polymer concentration is reported.