Toxic effects triggered by crotalic envenoming are mainly related to crotoxin (CTX), composed of a phospholipase A₂ (CB) and a subunit with no toxic activity (CA). Camelids produce immunoglobulins G devoid of light chains, in which the antigen recognition domain is called VHH. Given their unique characteristics, VHHs were selected using Phage Display against CTX from Crotalus durissus terrificus. After three rounds of biopanning, four sequence profiles for CB (KF498602, KF498603, KF498604, and KF498605) and one for CA (KF498606) were revealed. All clones presented the VHH hallmark in FR2 and a long CDR3, with the exception of KF498606. After expressing pET22b-VHHs in E. coli, approximately 2 to 6 mg of protein per liter of culture were obtained. When tested for cross-reactivity, VHHs presented specificity for the Crotalus genus and were capable of recognizing CB through Western blot. KF498602 and KF498604 showed thermostability, and displayed affinity constants for CTX in the micro or nanomolar range. They inhibited in vitro CTX PLA₂ activity, and CB cytotoxicity. Furthermore, KF498604 inhibited the CTX-induced myotoxicity in mice by 78.8%. Molecular docking revealed that KF498604 interacts with the CA–CB interface of CTX, seeming to block substrate access. Selected VHHs may be alternatives for the crotalic envenoming treatment.

In order to address the global antivenom crisis, novel antivenoms need to present high therapeutic efficacy, broad neutralization ability against systemic and local damage, sufficient safety, and cost‐effectiveness. Due to biological characteristics of camelid single‐domain antibodies (VHH) such as high affinity, their ability to penetrate dense tissues, and facility for genetic manipulation, their application in antivenoms has expanded considerably. VHHs that are active against the metalloprotease BjussuMP‐II from the snake Bothrops jararacussu were selected. After isolation of BjussuMP‐II, a camelid was immunized with the purified toxin in order to construct the recombinant phage library. Following a round of biopanning, 52% of the selected clones were able to recognize BjussuMP‐II in an ELISA assay. After sequencing, seven sequence profiles were identified. One selected clone (VHH61) showed cross‐reactivity to B. brazili venom, but did not recognize the Crotalus and Lachesis genera, indicating specificity for the Bothrops genus. Through in vitro tests, the capacity to neutralize the toxicity triggered by BjussuMP‐II was observed. Circular dichroism spectroscopy indicated a robust secondary structure for VHH61, and the calculated melting temperature (T_M) for the clone was 56.4°C. In silico analysis, through molecular docking of anti‐BjussuMP‐II VHHs with metalloprotease, revealed their potential interaction with amino acids present in regions critical for the toxin’s conformation and stability. The findings suggest that anti‐BjussuMP‐II VHHs may be beneficial in the development of next‐generation antivenoms.

A presença de fármacos quimioterápicos nos efluentes dos estabelecimentos de assistência à saúde podem ser uma expressiva fonte responsável pela entrada destes no ambiente aquático. Estes compostos são classificados como micropoluentes orgânicos emergentes (MPOE) e seu processo de degradação no ambiente e sua ecotoxicidade ainda são pouco conhecidos. Considerando o aumento no número de casos de neoplasias e do surgimento de novas composições farmacológicas, é importante que a legislação esteja em consonância com a situação, regulamentando a presença destes compostos no ambiente. O objetivo foi discutir o conjunto de regulamentações em vigor acerca do lançamento de efluentes com quimioterápicos antineoplásicos em águas superficiais, identificando, a partir de critérios técnicos, lacunas existentes na legislação nacional e estadual de Rondônia. A metodologia foi a de revisão sistemática de literatura com ênfase em estudos que apresentaram dados de identificação e quantificação de compostos antineoplásicos liberados por excretas humanas, implicações ambientais e sobre exigências em legislação regulamentares para lançamento de efluentes hospitalares. a legislação brasileira ainda é insipiente no que tange à regulamentação e vigilância de efluentes contendo fármacos e/ou seus metabólitos, haja vista que os dispositivos legais e normativos federais e estaduais não abordam padrões de lançamento para estes compostos, nem limites de detecção. A Resolução CONAMA 430/2011 e a RDC ANVISA 222/2018 são os normativos que mais se aproximam do tema, porém ainda inconsistentes quanto a critérios de tratamento, lançamento ou monitoramento de efluentes hospitalares.

Snakebite envenoming remains an important global public health problem, and Brazil ranks among the countries with the highest notification rates, especially in the Northern region. Therapeutic intervention is decisive in snakebite cases, as early administration of antivenom reduces the severity of systemic and local manifestations. However, in the absence of a diagnostic test, identification of the snake responsible for envenoming remains restricted to clinical and epidemiological assessment. In this context, this study demonstrates the potential for developing a diagnostic assay for snakebite envenoming using nanobioconjugates composed of antivenom VHHs against rattlesnakes and jararacas, medically important snakes in the country. In dot blot assays, the anti-Bothrops nanobioconjugates showed visible reactivity against Bothrops jararacussu venom down to 10 ng/µL and more consistent reactivity at concentrations ≥ 50 ng/µL. The anti-Crotalus nanobioconjugates detected Crotalus durissus terrificus venom at concentrations as low as 400 ng/µL and also showed reactivity toward three additional Crotalus subspecies venoms. In control assays, no cross-reactivity was observed with the heterologous venoms evaluated. These results provide initial evidence for the potential use of VHH-based nanobioconjugates for venom detection, while indicating that further optimization of analytical sensitivity is required before clinical application.