Polymicrobial biofilms adhere to surfaces and enhance pathogen resistance to conventional treatments, significantly contributing to chronic infections in the respiratory tract, oral cavity, chronic wounds, and on medical devices. This review examines antimicrobial peptides (AMPs) as a promising alternative to traditional antibiotics for treating biofilm‐associated infections. AMPs, which can be produced as part of the innate immune response or synthesized therapeutically, have broad‐spectrum antimicrobial activity, often disrupting microbial cell membranes and causing cell death. Many specifically target negatively charged bacterial membranes, unlike host cell membranes. Research shows AMPs effectively inhibit and disrupt polymicrobial biofilms and can enhance conventional antibiotics' efficacy. Preclinical and clinical research is advancing, with animal studies and clinical trials showing promise against multidrug‐resistant bacteria and fungi. Numerous patents indicate increasing interest in AMPs. However, challenges such as peptide stability, potential cytotoxicity, and high production costs must be addressed. Ongoing research focuses on optimizing AMP structures, enhancing stability, and developing cost‐effective production methods. In summary, AMPs offer a novel approach to combating biofilm‐associated infections, with their unique mechanisms and synergistic potential with existing antibiotics positioning them as promising candidates for future treatments.

The search for new antimicrobial agents is a continuous struggle, mainly because more and more cases of resistant strains are being reported. Mycobacterium tuberculosis (MTB) is the main microorganism responsible for millions of deaths worldwide. The development of new antimicrobial agents is generally aimed at finding strong interactions with one or more bacterial receptors. It has been proven that bacteriophages have the ability to adhere to specific and selective regions. However, their transport and administration must be carefully evaluated as an excess could prevent a positive response and the bacteriophages may be eliminated during their journey. With this in mind, the mycobacteriophage D29 was encapsulated in nanoliposomes, which made it possible to determine its antimicrobial activity during transport and its stability in the treatment of active and latent Mycobacterium tuberculosis. The antimicrobial activity, the cytotoxicity in macrophages and fibroblasts, as well as their infection and time–kill were evaluated. Phage nanoencapsulation showed efficient cell internalization to induce MTB clearance with values greater than 90%. Therefore, it was shown that nanotechnology is capable of assisting in the activity of degradation-sensitive compounds to achieve better therapy and evade the immune response against phages during treatment.

Tuberculosis (TB), caused by Mycobacterium tuberculosis (MTB), remains one of the most devastating infectious diseases worldwide, with rising multidrug resistance limiting the effectiveness of conventional treatments. Novel therapeutic approaches are urgently needed to complement or replace existing regimens. Among emerging candidates, antimicrobial peptides (AMPs) stand out as versatile molecules capable of exerting direct antimycobacterial effects while also modulating the host immune response. This review explores peptide-based strategies against TB, with a focus on four major axes of innovation. First, we examine host-directed pathways, including the vitamin D–cathelicidin axis and other immunomodulatory mechanisms and their regulatory role in the induction of endogenous AMPs such as cathelicidin LL-37, which contributes to host-directed defense. Second, we discuss peptide-based vaccines designed to elicit robust and durable protective immunity, representing a complementary alternative to classical vaccine approaches. Third, we highlight the synergistic potential of AMPs in combination with first-line and second-line anti-TB drugs, aiming to restore or enhance bactericidal activity against resistant strains. Finally, we analyze technological platforms, including nanocarriers and inhalable formulations, that enable targeted pulmonary delivery, improve peptide stability, and enhance bioavailability. By integrating molecular design, immune modulation, and advanced delivery systems, peptide-based strategies provide a multifaceted approach to overcoming the limitations of current TB therapy. Collectively, these advances position AMPs not only as promising standalone agents but also as key components in combination and host-directed therapies, with strong potential to reshape the future clinical management of tuberculosis.

Gastrointestinal infections, which are caused primarily by pathogenic bacteria, remain a significant global health challenge. Their resilience is reinforced by various physical, biological, and biopharmaceutical barriers that complicate conventional therapeutic strategies. This review delves into the intricate landscape of managing these infections, addressing microbiota imbalances, the emergence of multidrug‐resistant strains, and the impact of dysbiosis and antibiotic overuse. Faced with these challenges, traditional therapies often fail, which is hindered by low bioavailability, prolonged regimens, and a growing risk of resistance. In this context, nanotechnology applied to antimicrobial peptides (AMPs) has emerged as a promising solution to enhance their stability and targeted delivery. Through a critical approach, diverse nanocarriers and their efficacy against intestinal pathogens are evaluated both in vitro and in vivo. This review advocates for intensified research on the encapsulation and functionalization of AMPs, envisioning their potential to redefine the control of intestinal infections on a global scale.

The infectious agent Mycobacterium tuberculosis (MTB) has several defense and resistance mechanisms that must be eliminated. The treatment is prolonged, which in many cases generates susceptibility to microbial resistance. This research aimed to study whether the antimicrobial peptide Ctx(Ile²¹)-Ha-Ahx-Cys (Ctx-SH) functionalized in nanochitosan matrices could eliminate resistant MTB. For this, a nanosystem was developed with chitosan matrices previously modified with N-acetylcysteine functionalized to Ctx-SH. Modified chitosan nanoparticles (NPQ) were obtained by ionic gelation using sodium tripolyphosphate and loaded with rifampicin. Both chitosan and NPQ modifications were analyzed for physicochemical parameters by Fourier/Raman transform infrared spectroscopy and Zeta potential. Antimicrobial activity was performed in a level 3 biosafety laboratory with strains H37Rv (standard) and CF169 (extensively drug-resistant, XDR) incubated in 7H9 broth supplemented with oleic acid, albumin, dextrose, and catalase at 37 °C and 5% CO₂ and read using fluorescence with 0.01% resazurin after 7 days. Insertion and mapping of NPQ into macrophages were assessed using a confocal microscope after 24 h with NPQ conjugated to fluorescein isothiocyanate. Preliminary results show that the spectroscopies corroborate the hypothesis of the functionalization of the Ctx-SH peptide to the chitosan-N-acetylcysteine system because, when comparing the three spectroscopies, a gradual increase in the intensity of several bands and the formation of captive disulfide are observed, and the Zeta potential (+30 mV) confirmed high application stability. Bacterial inhibition studies revealed that rifampicin-loaded antimicrobial peptide-conjugated chitosan nanoparticles have better activity than rifampicin alone against CF169, with a minimum inhibitory concentration of <0.977 µg/mL, similar to the standard strain. In addition, it was shown that NPQ would be able to enter the macrophage without causing toxicity and thus take better advantage of the activity of rifampicin. Finally, it is possible to verify that the nanobioconjugation of the Ctx-SH-N-acetylcysteine-chitosan compound is capable of enhancing the activity of obsolete drugs and/or sensitizing XDR bacteria.