Biocompatible polymeric materials with potential to form functional structures in association with different therapeutic molecules have a high potential for biological, medical and pharmaceutical applications. Therefore, the protective capability of the inclusion nano-Complex formed between the sodium salt of poly(maleic acid-alt-octadecene) and a β-lactam drug (ampicillin trihydrate) on the chemical, enzymatic and biological degradation was evaluated. PAM-18Na was produced and characterized as reported previously. The formation of polymeric hydrophobic aggregates in aqueous solution was determined, using pyrene as a fluorescent probe. Furthermore, the formation of polymer-drug nano-complexes was characterized by Differential Scanning Calorimetry-DSC, viscometric, ultrafiltration/centrifugation assays, zeta potential and size measurements by dynamic light scattering-DLS. The PAM-18Na capacity to avoid the chemical degradation was studied through stress stability tests. The enzymatic degradation was evaluated from a pure β-lactamase, while the biological degradation was determined by different β-lactamase producing Staphylococcus aureus strains. When ampicillin was associated with PAM-18Na, the half-life time in acidic conditions increased, whereas both the enzymatic degradation and the minimum inhibitory concentration decreased to a 90 and 75%, respectively. These results suggest a promissory capability of this polymer to protect the β-lactam drugs against chemical, enzymatic and biological degradation.

According to the International Union for Conservation of Nature Red List, the scalloped hammerhead (Sphyrna lewini) is a critically endangered species, primarily due to intense fishing and other anthropogenic effects such as pollution. Nowadays, plastic debris contamination is a subject of concern due to its extensive presence in the sea and the digestive tracts of many fish species. The possible effects of plastic debris as a vector of other pollutants are still unknown. We analyzed the digestive tract of hammerhead sharks to investigate the correlation between plastic and other anthropic debris contamination and feeding habits in the eastern region of the Gulf of California. A total of 58 specimens were analyzed from the coastal area, revealing a plastic occurrence frequency of 79.3%. Of these, 91.4% corresponded to fibers, and 8.6% to fragments. The composition of the polymers was primarily cellulose (64.4%). According to their diet, these organisms exhibit benthopelagic habits, feeding both in the water column and on the seabed. These results indicate a high level of contamination of anthropogenic cellulosic microfibers in the area. This changed according to the year, indicating that the anthropic debris ingestion is related to the discharges of human activities and their seasonality rather than to a selection process by the sharks. Although cellulosic microfibers are recognized as a biomaterial, they can harm marine species, posing an additional threat to this iconic shark.