Tissue Sources Influence the Morphological and Morphometric Characteristics of Collagen Membranes for Guided Bone Regeneration

(1) Background: Collagen, a natural polymer, is widely used in the fabrication of membranes for guided bone regeneration (GBR). These membranes are sourced from various tissues, such as skin, pericardium, peritoneum, and tendons, which exhibit differences in regenerative outcomes. Therefore, this study aimed to evaluate the morphological and chemical properties of porcine collagen membranes from five different tissue sources: skin, pericardium, dermis, tendons, and peritoneum. (2) Methods: The membrane structure was analyzed using energy-dispersive X-ray spectrometry (EDX), variable pressure scanning electron microscopy (VP-SEM), Fourier transform infrared spectroscopy (FTIR), and thermal stability via thermogravimetric analysis (TGA). The absorption capacity of the membranes for GBR was also assessed using an analytical digital balance. (3) Results: The membranes displayed distinct microstructural features. Skin- and tendon-derived membranes had rough surfaces with nanopores (1.44 ± 1.24 µm and 0.46 ± 0.1 µm, respectively), while pericardium- and dermis-derived membranes exhibited rough surfaces with macropores (78.90 ± 75.89 µm and 64.89 ± 13.15 µm, respectively). The peritoneum-derived membrane featured a rough surface of compact longitudinal fibers with irregular macropores (9.02 ± 3.70 µm). The thickness varied significantly among the membranes, showing differences in absorption capacity. The pericardium membrane exhibited the highest absorption, increasing by more than 10 times its initial mass. In contrast, the skin-derived membrane demonstrated the lowest absorption, increasing by less than 4 times its initial mass. Chemical analysis revealed that all membranes were primarily composed of carbon, nitrogen, and oxygen. Thermogravimetric and differential scanning calorimetry analyses showed no significant compositional differences among the membranes. FTIR spectra confirmed the presence of collagen, with characteristic peaks corresponding to Amide A, B, I, II, and III. (4) Conclusions: The tissue origin of collagen membranes significantly influences their morphological characteristics, which may, in turn, affect their osteogenic properties. These findings provide valuable insights into the selection of collagen membranes for GBR applications.