Engineering oncogene-targeted anisamide-functionalized pBAE nanoparticles as efficient lung cancer antisense therapies

Non-small cell lung cancer (NSCLC) is one of the leading causes of worldwide death, mainly due to the lack of efficient and safe therapies. Currently, NSCLC standard of care for consist on the use of traditional chemotherapeutics, non-selectively distributed through the whole body, thus causing severe side effects while not achieving high efficacy outcomes. Consequently, the need of novel therapies, targeted to modify specific subcellular routes aberrantly expressed only in tumor cells is still urgent. In this context, the delivery of siRNAs that can know-down overexpressed oncogenes, such as mTOR, could become the promised targeted therapy. However, siRNA effective delivery remains a challenge due to its compromised stability in biological fluids and its inability to cross biological and plasmatic membranes. Therefore, polymeric nanoparticles that efficiently encapsulate siRNAs and are selectively targeted to tumor cells could play a pivotal role. Accordingly, we demonstrate in this work that oligopeptide end-modified poly(beta aminoester) (OM-pBAE) polymers can efficiently complex siRNA in small nanometric particles using very low polymer amounts, protecting siRNA from nucleases attack. These nanoparticles are stable in the presence of serum, advantageous fact in terms of in vivo use. We also demonstrated that they efficiently transfect cells in vitro, in the presence of serum and are able to knock down target gene expression. Moreover, we demonstrated their antitumor efficacy by encapsulating mTOR siRNA, as a model antisense therapy, which showed specific lung tumor cell growth inhibition in vitro and in vivo. Finally, through the addition of anisamide functionalization to the surface of the nanoparticles, we proved that they become selective to lung tumor cells, while not affecting healthy cells. Therefore, our results are a first step in the discovery of a tumor cell-targeted efficient silencing nanotherapy for NSCLC patients survival improvement.

Synthesis and Characterization of mRNA-Loaded Poly(Beta Aminoesters) Nanoparticles for Vaccination Purposes

Vaccination has been one of the major successes of modern society and is indispensable in controlling and preventing disease. Traditional vaccines were composed of entire or fractions of the infectious agent. However, challenges remain, and new vaccine technologies are mandatory. In this context, the use of mRNA for immunizing purposes has shown an enhanced performance, as demonstrated by the speedy approval of two mRNA vaccines preventing SARS-CoV-2 infection. Beyond success in preventing viral infections, mRNA vaccines can also be used for therapeutic cancer applications. Nevertheless, the instability of mRNA and its fast clearance from the body due to the presence of nucleases makes its naked delivery not possible. In this context, nanomedicines, and specifically polymeric nanoparticles, are critical mRNA delivery systems. Thus, the aim of this article is to describe the protocol for the formulation and test of an mRNA vaccine candidate based on the proprietary polymeric nanoparticles. The synthesis and chemical characterization of the poly(beta aminoesters) polymers used, their complexation with mRNA to form nanoparticles, and their lyophilization methodology will be discussed here. This is a crucial step for decreasing storage and distribution costs. Finally, the required tests to demonstrate their capacity to in vitro transfect and mature model dendritic cells will be indicated. This protocol will benefit the scientific community working on vaccination because of its high versatility that enables these vaccines to prevent or cure a wide variety of diseases.

Provision of urea–molasses blocks to improve smallholder cattle weight gain during the late dry season in tropical developing countries: studies from Lao PDR

Context Large-ruminant production in developing countries is inefficient with low growth rates and declining weights, particularly in the dry season. Aims The impact of ad libitum supplementation of cattle with high-quality molasses blocks (20 kg) containing either 8% urea (UMB) or nil urea (MB), was examined. Methods Field trials on smallholder farms compared weight changes and average daily gains (ADG = g/day) data of young calves <8 months of age (n = 25); growing calves 8–24 months (n = 35) and lactating cows (n = 46), of the indigenous breed when accessing either UMB or MB, with data being collected at Weeks 1, 4, 8 and 12. A pen study was also conducted at a research station involving mature, lactating crossbred cows (n = 37). Surveys of farming families experiencing use of the blocks was conducted (n = 20). Key results On smallholder farms, animals accessing UMBs were heavier than those accessing MBs at every collection day and in young calves these differences were statistically significant (P < 0.05). ADGs were higher in cattle accessing UMB than in those accessing MBs. Young calves had the highest ADG (251–265 g/day), followed by growing calves (198–237 g/day) and lactating cows (187–190 g/day), although differences in ADG between UMB and MB cohorts were not considered significant (young calves P = 0.562; growing calves P = 0.509; and lactating cows P = 0.993). Results from the pen study identified that ADGs were not significantly different (P = 0.933) between crossbred cows accessing MBs (236 g/day) and cows accessing UMBs (229 g/day). Surveys of farmers using blocks confirmed that their animals were calmer and healthier, and had better coat condition with minimal external parasites; these farmers wished to purchase the blocks and were willing to pay a mean up to US$6.5 ± 2.3 per block. Conclusions Provision of UMBs and MBs in Laos in the late dry season improved cattle growth rates, which is consistent with previous studies and far superior to the base-line data from Laos demonstrating declining ADGs. Farmers considered that the blocks contributed greatly to herd management and improved sale-ability of their cattle. Implications Provision of molasses blocks on low-input smallholder farms in developing countries significantly improves production efficiency, offering an ‘entry point’ intervention while forages are becoming established.

Can fenbendazole-medicated molasses blocks control Toxocara vitulorum in smallholder cattle and buffalo calves in developing countries? Studies from upland Lao PDR

Context Anthelmintic treatments are not widely adopted by smallholder farmers in Laos (Lao People’s Democratic Republic) to treat bovid Toxocara vitulorum, resulting in high calf morbidity and mortality. Aims Field trials were conducted to provide baseline efficacy data on an alternative, easy-to-use treatment by provision of fenbendazole-medicated molasses blocks (FMB) in situ. Methods Participating villages were randomly allocated to the following treatments: (1) conventional orally administered pyrantel, (2) access to FMB, (3) access to non-medicated molasses blocks (MB), and (4) no blocks (control). Faecal eggs per gram (EPG) and weight were monitored in cattle (n = 171) and buffalo calves (n = 44) under field conditions for 48–56 days. Key results In 2016, the MB treatment was associated with the fastest reduction in predicted average EPG at 2% per day, while FMB and pyrantel had an equivalent reduction of 1% per day, relative to the control (P = 0.062). Predicted average weight also differed significantly among treatments, with pyrantel and MB having the greatest average daily gain at 230 g and FMB at 200 g, which was higher than for control calves at 170 g (P = 0.002). In buffalo calves, treatment was not significantly associated with EPG or weight. The 2018 trial corroborated that FMB and MB treatments were associated with increased EPG reductions in cattle at 3% per day, relative to control calves (P = 0.007). Again, the MB treatment had the greatest predicted average daily gain at 200 g, compared with FMB calves at 160 g and control calves at 150 g (P = 0.005). Conclusions The field trials provided baseline evidence that FMB and MB have potential applications in reducing environmental contamination of T. vitulorum eggs and may improve calf growth in low-input systems. However, further testing ex situ is required to control for variability in calf weight and T. vitulorum burdens, so as to optimise anthelmintic doses, assess the addition of urea to the block formula and assess product marketability. Implications If successful, medicated nutrient blocks may be a simple method to reduce calf mortality and morbidity, enhancing the reproductive efficiency of large ruminant production in smallholder farms in developing countries.

Investigation of infectious reproductive pathogens of large ruminants: Are neosporosis, brucellosis, leptospirosis and BVDV of relevance in Lao PDR?

N. caninum, bovine viral diarrhoea virus, Brucella abortus and Leptospira interrogans serovar Hardjo are globally significant reproductive pathogens that cause abortion and reproductive loss in large ruminants. Prevalence information is lacking in Lao People's Democratic Republic (Laos) despite the poor reproductive performance of cattle and buffalo. Serological examination of frozen cattle (n=90) and buffalo (n=61) sera by commercially available enzyme-linked immunosorbent assays provided the first reported screening of some of these pathogens in Laos. Seroprevalence differed amongst these large ruminant species, with N. caninum, BVDV and L. interrogans serovar Hardjo antibodies found in 68.9% (95% CI±11.6), 4.9% (95% CI±5.4) and 3.3% (95% CI±4.5) of buffalo sera, respectively, and in 7.8% (95% CI±5.5), 10.0% (95% CI±6.2) and 22.2% (95% CI±8.6) of cattle sera, respectively. Buffalo sera had a significantly higher seroprevalence of N. caninum compared to cattle (p<0.001) and cattle sera had a significantly higher seroprevalence of L. interrogans serovar Hardjo compared to buffalo (p=0.003). Variability was also observed across provinces for N. caninum in buffalo (p=0.007) and for L. interrogans serovar Hardjo in cattle (p=0.071), suggesting provincial risk factors conducive to pathogen transmission. BVDV and N. caninum seropositivity were negatively associated in buffalo (p=0.018) and cattle (p=0.003). In buffalo, L. interrogans serovar Hardjo and BVDV seropositivity were associated (p=0.035, p=0.039). The identification of antibodies against three major abortifacient pathogens in Laos prompts further research to determine if infection is associated with low reproductive efficiency and the risk factors for infection. This is needed for the development of evidence based prevention strategies for improved large ruminant reproductive management among smallholders in Laos.

Investigation of smallholder farmer biosecurity and implications for sustainable foot-and-mouth disease control in Cambodia

In Cambodia, the majority of the population is rural and reliant on subsistence agriculture, with cattle raised by smallholder farmers using traditional practices, resulting in low productivity and vulnerability to foot-and-mouth disease (FMD). As FMD causes deleterious impacts on rural livelihoods, known FMD risk factors were reviewed, using knowledge, attitudes and practice (KAP) surveys of smallholders (n = 240) from four regions. The study aimed to understand current biosecurity threats to smallholder livelihoods and investigate the hypothesis that smallholder farmers practising FMD risk management should be associated with higher incomes from cattle. Descriptive data were examined to demonstrate trends in KAP and a multivariable linear regression model developed to identify cattle income predictors. Results showed that baseline mean knowledge scores were low at 28.4% across all regions and basic biosecurity practices, including quarantine of new cattle, isolation of sick cattle and FMD vaccination, were lacking. As farmers purchase and sell cattle from and to various administration levels (including export), there is high risk of FMD transmission into and from smallholder communities. The final multivariable linear regression model identified significant explanatory parameters for annual cattle income, including region, number of calves born, forage plot size (ha), vaccination of cattle and the number of cattle purchased (F pr. < 0.001, R²  = 29.9). Individual biosecurity practices including FMD vaccination were not significant predictors of income. With the current focus of farmers on treatment of FMD with inappropriate antibiotics leading to potential anti-microbial residue issues, yet receptivity to payment for vaccine in most regions, there is an urgent need for a coordinated national biosecurity and FMD management public awareness campaign. Further, to enhance the association between improved cattle health and rural livelihoods, it is recommended that livestock development programmes implement a systems approach to enhance farmer KAP in biosecurity, nutrition, reproduction and marketing of cattle.