The development of new food preservatives is essential to prevent foodborne outbreaks or food spoilage due to microbial growth, enzymatic activity or oxidation. Furthermore, new compounds that substitute the commonly used synthetic food preservatives are needed to stifle the rising problem of microbial resistance. In this scenario, we report herein, as far as we know, for the first time the use of the zein protein as a gating moiety and its application for the controlled release of essential oil components (EOCs). The design of microdevices consist of mesoporous silica particles loaded with essential oils components (thymol, carvacrol and cinnamaldehyde) and functionalized with the zein (prolamin) protein found in corn as a molecular gate. The zein protein grafted on the synthesized microdevices is degraded by the proteolytic action of bacterial enzymatic secretions with the consequent release of the loaded essential oil components efficiently inhibiting bacterial growth. The results allow us to conclude that the new microdevice presented here loaded with the essential oil component cinnamaldehyde improved the antimicrobial properties of the free compound by decreasing volatility and increasing local concentration.

Pathogenic microorganisms can adhere to solid surfaces, leading to the formation of biofilms, thus building a physical barrier hindering the penetration and diffusion of antimicrobial compounds. In this context, the use of natural antimicrobial compounds, such as essential oil components, as substitutes for common synthetic antimicrobials in the fight to prevent antimicrobial resistance is explored. As stainless steel is one of the most widely used surfaces in different industries, we have developed an innovative antimicrobial treatment for stainless steel surfaces based on a multi-step functionalization process, in which the stainless steel surface is coated with a silica layer to which a vanillin derivative is covalently attached. The surface was analyzed by microscopy studies, indicating the correct immobilization on the surfaces. Antimicrobial studies (viability and bacterial adhesion assays) were performed against the bacteria Staphylococcus epidermidis, which is one of the most frequent causes of nosocomial infections. The results of the microbiological studies showed that vanillin-functionalized stainless steel surfaces reduce the bacteria viability by 100% and the biofilm formation on the stainless steel surface by 75% compared with non-functionalized surfaces, highlighting the contact-killing and adhesion resistance properties of the developed surface. Additional cycles using the functionalized surfaces showed good maintenance of the antimicrobial coating efficacy. Moreover, the surfaces coated with an intermediate silica layer demonstrated much greater antimicrobial activity than surfaces in which the active molecule was directly functionalized on the stainless steel surface.

Metastatic prostate cancer (mPC) is a lethal disease; most therapeutic options focus on androgen receptor signaling inhibition, but resistance eventually arises. Cyclin-dependent kinase 4 and 6 inhibitors (CDK4/6i) have shown antitumor efficacy in mPC preclinical models, but their efficacy in mPC clinical trials has been limited. We hypothesize that novel combination therapies designed leveraging mPC adaptation to CDK4/6i could lead to increased and sustained antitumor effect. In this study, we demonstrate in a range of in vitro and in vivo prostate cancer models, including patient-derived xenografts, that prostate cancer cells adopt a senescent phenotype upon CDK4/6 inhibition that can be selectively targeted using senolytic compounds. Notably, interrupting CDK4/6 inhibition in intermittent drug schedules prompts a rapid bypass of the senescent phenotype that is associated with a temporal downregulation of replisome proteins in Rb-proficient but not in Rb-deficient models, leading to DNA damage accumulation and replication stress following treatment withdrawal. This effect opens a window of opportunity for treatment with PARP inhibitors (PARPi): Although upfront combined inhibition of CDK4/6 and PARP1 had no antitumor effect, their sequential use adding PARPi upon CDK4/6i withdrawal and cell-cycle reentry results in major antitumor activity. Our findings underscore the potential of CDK4/6i in prostate cancer therapy, particularly when administered under biology-driven sequential use of senolytic therapy or PARPi. Such strategic interventions hold promise in overcoming resistance and enhancing treatment outcomes for patients with advanced prostate cancer and open avenues for repurposing CDK4/6i therapy in mPC.

Information for non-FDA-approved agents used in the study

Senolytic index (SI) values palbociclib

Engineering vesicle-based artificial cells capable of mimicking cellular processes is a central objective in synthetic biology. However, while giant unilamellar vesicles (GUVs) have become a popular artificial cell platform, the impact of fundamental design features remains obscure. Here, we assembled GUVs composed primarily of two phospholipids: POPC, a phosphatidylcholine widely employed in GUV preparation, and DOPC, a phosphatidylcholine with a lower melting temperature and higher fluidity. We found that the phospholipid mixture leads to an increase in average GUV size (compared to POPC only) without compromising GUV yield (in contrast to DOPC only). Moreover, we studied two artificial cell functions: enzyme-driven protein-membrane docking and protein expression. Artificial cells prepared from the phospholipid mixture exhibited enhanced relocation of proteins to the membrane and enhanced protein expression. Furthermore, our data allowed us to identify the limiting factor that underlies the observed differences in protein expression between membrane formulations: the efficiency of macromolecular encapsulation. Altogether, our study underscores the importance of membrane engineering as a powerful strategy for advancing the rational development of artificial cells with functional capabilities.