Bispecific antibody complex pre-targeted delivery of polymer–drug conjugates for cancer therapy

Polymeric Nanoparticle Based Diagnosis and Nanomedicine for Treatment and Development of Vaccines for Cerebral Malaria: A Review on Recent Advancement

Cerebral malaria occurs due to Plasmodium falciparum infection, which causes 228 million infections and 450,000 deaths worldwide every year. African people are mostly affected with nearly 91% cases, of which 86% are pregnant women and infants. India and Brazil are the other two countries severely suffering from malaria endemicity. Commonly used drugs have severe side effects, and unfortunately no suitable vaccine is available in the market today. In this line, this review is focused on polymeric nanomaterials and nanocapsules that can be used for the development of effective diagnostic strategies, nanomedicines, and vaccines in the management of cerebral malaria. Further, this review will help scientists and medical professionals by updating the status on the development stages of polymeric nanoparticle based diagnostics, nanomedicines, and vaccines and strategies to eradicate cerebral malaria. In addition to this, the predominant focus of this review is antimalarial agents based on polymer nanomedicines that are currently in the preclinical and clinical trial stages, and potential developments are suggested as well. This review further will have an important social and commercial impact worldwide for the development of polymeric nanomedicines and strategies for the treatment of cerebral malaria.

Imaging doxorubicin and polymer-drug conjugates of doxorubicin-induced cardiotoxicity with bispecific anti-myosin-anti-DTPA antibody and Tc-99m-labeled polymers

BACKGROUND

Radiolabeled anti-myosin imaging is well-established for imaging doxorubicin-induced cardiotoxicity. However, to enable imaging of drug-induced cardiotoxicity in small experimental animals, pretargeting with bispecific anti-myosin-anti-DTPA-Fab-Fab' and targeting with high-specific radioactivity Tc-99m-DTPA-succinylated-polylysine (DSPL) was developed.

METHODS

Mice were injected biweekly with 10 mg/kg Dox or its equivalent as D-Dox-PGA. Tc-99m-DSPL myocardial activity after pretargeting with bsAb-Fab-Fab' was determined after gamma imaging performed at day 7 for Dox-treated mice and day 39 for all others.

RESULTS

Mice treated with 10 mg/kg Dox lost 10% total body weight in 1 week and 20% after a second dose. Pretargeted mice treated with 30 mg/kg cumulative D-Dox-PGA dose showed no loss of body weight for the duration of the study. Cardiotoxicity was confirmed by gamma imaging and scintillation counting (1.9 ± 0.25 [mean% ID/g ± SD]) after 1 dose of Dox. Mice injected with 3 × 10 mg/kg Dox equivalent as D-Dox-PGA (0.4 ± 0.04, P < .01) and untreated 2 control groups (0.20 ± 0.05 and 0.19 ± 0.04, P < .01) showed significantly lower myocardial anti-myosin radioactivity relative to the 10 mg/kg Dox group.

CONCLUSION

Pretargeting with bsAb-Fab-Fab' and targeting with Tc-99m labeled high-specific activity polymers enabled early visualization of doxorubicin induce cardiotoxicity in mice. Tolerated dose of D-Dox-PGA was greater than to 30 mg/kg Dox-equivalent dose with minimal cardiotoxicity.

A review of bispecific antibodies and antibody constructs in oncology and clinical challenges

Bispecific antibodies (bsAbs) are antibodies that bind two distinct epitopes to cancer.. For use in oncology, one bsAb has been approved and 57 bsAbs are in clinical trials, none of which has reached phase 3. These bsAbs show great variability in design and mechanism of action. The various designs are often linked to the mechanisms of actions. The majority of bsAbs engage immune cells to destroy tumor cells. However, some bsAbs are also used to deliver payloads to tumors or to block tumor signaling pathways. This review provides insight into the choice of construct for bsAbs, summarizes the clinical development of bsAbs in oncology and identifies subsequent challenges.

Affibody molecules for molecular imaging and targeted drug delivery in the management of breast cancer

Breast cancer is one of the leading reasons for the morbidity and mortality of cancer related death globally. The modern therapies are basically the combination of the breast-preserving surgeries or ablation with or without node biopsy or destroying the carcinoma cells adjuvant with chemotherapy, radiotherapy, hormonal or biological therapies depending upon the nature of the receptor of the cancerous cells, nature of the lymph node, as well as the tendency of the recurrence. For decade's carcinoma management suffered by the limitation of imagining, targeting and penetrability problem associated with management and cure of this deadly disease leads to unwanted chemo-toxicity and side effects. Alike other antibody mimetics, affibodies are designed with the combinatorial protein engineering approaches which are small and robust protein scaffolds retaining the favorable folding and stability. Affibody is one of the significantly important tools for imaging and diagnosis of the affinity specific over expressed proteins in the breast cancer management. The review summarizes the various affibody strategies uses in the management of breast cancer.

Addressing challenges of heterogeneous tumor treatment through bispecific protein-mediated pretargeted drug delivery

Tumors are frequently characterized by genomically and phenotypically distinct cancer cell subpopulations within the same tumor or between tumor lesions, a phenomenon termed tumor heterogeneity. These diverse cancer cell populations pose a major challenge to targeted delivery of diagnostic and/or therapeutic agents, as the conventional approach of conjugating individual ligands to nanoparticles is often unable to facilitate intracellular delivery to the full spectrum of cancer cells present in a given tumor lesion or patient. As a result, many cancers are only partially suppressed, leading to eventual tumor regrowth and/or the development of drug-resistant tumors. Pretargeting (multistep targeting) approaches involving the administration of 1) a cocktail of bispecific proteins that can collectively bind to the entirety of a mixed tumor population followed by 2) nanoparticles containing therapeutic and/or diagnostic agents that can bind to the bispecific proteins accumulated on the surface of target cells offer the potential to overcome many of the challenges associated with drug delivery to heterogeneous tumors. Despite its considerable success in improving the efficacy of radioimmunotherapy, the pretargeting strategy remains underexplored for a majority of nanoparticle therapeutic applications, especially for targeted delivery to heterogeneous tumors. In this review, we will present concepts in tumor heterogeneity, the shortcomings of conventional targeted systems, lessons learned from pretargeted radioimmunotherapy, and important considerations for harnessing the pretargeting strategy to improve nanoparticle delivery to heterogeneous tumors.

Real-time imaging of intracellular drug release from mesoporous silica nanoparticles based on fluorescence resonance energy transfer

A multifunctional nanodevice is designed based on doxorubicin (DOX)-loaded green fluorescent mesoporous silica nanoparticles (FMSN) conjugated with folic acid (FA). Real-time monitoring of intracellular drug release based on fluorescence resonance energy transfer is achieved.