Polymer-drug conjugates containing antimalarial drugs and antibiotics

Treatment outcomes of patients with uncomplicated malaria and associated factors in Northwest Ethiopia: a prospective follow-up study, 2024

BACKGROUND

Malaria is the major public health problem in low-income countries like Ethiopia. Despite extensive interventional studies being conducted to attain the 2030 malaria elimination goals, there is limited data on the treatment outcomes of uncomplicated malaria in Ethiopia. Thus, this study aimed to assess the treatment outcomes and associated factors of uncomplicated malaria in Northwest Ethiopia.

METHODS

This study was conducted in two health centers, Kolla Diba and Forhe-Sankira, located in Dembia and North Achefer Districts, from April to June 2024. Data was collected from 460 study participants who presented with signs and symptoms and from parasitologically confirmed patients. Malaria was confirmed using microscopy and rapid diagnostic tests (RDT). The parasitologically confirmed patients were appointed on the 3rd, 7th, 14th, and 28th days to determine treatment outcomes for those who were parasitemic on the preceding visit or symptomatic at each visit. The collected longitudinal data was entered and cleaned by Epi-data 4.1 and then analyzed using SPSS 25 software. Descriptive statistics were computed. A binary logistic regression model was fitted to identify factors associated with unsuccessful treatment outcomes at a 95% CI, and a p-value ˂ 0.05 was considered significant.

RESULTS

Of the 460 study participants, 234 (50.9%) were parasitologically confirmed. Treatment outcomes were determined for 224 (95.7%) patients. Ten patients were lost to follow-up. The overall unsuccessful treatment rate was 18.8%. No previous malaria attack (AOR = 18.62, 95% CI: 5.15, 67.25), being infected by Plasmodium vivax (AOR = 8.58; 95% CI: 2.85, 25.83), and coartem two times for 3 days plus primaquine for 14 days (AOR = 4.84; 95% CI: 1.83, 12.79) were the identified factors for unsuccessful treatment outcomes.

CONCLUSIONS AND RECOMMENDATIONS

This study revealed that a higher proportion of patients had an unsuccessful treatment outcome. No previous malarial attack, being infected by Plasmodium vivax, and coartem plus primaquine were the identified factors for unsuccessful treatment outcomes. We recommend that healthcare providers prescribe first-line antimalarial therapy and appoint patients for follow-up evaluation according to the national guidelines to identify treatment failure early.

Antibacterial activity of a silver-incorporated vancomycin-modified mesoporous silica against methicillin-resistant Staphylococcus aureus

Since conventional antibiotics are almost ineffective on methicillin-resistant Staphylococcus aureus (MRSA) strains, designing their antibacterial alternatives is necessary. Besides, the use of vancomycin is applied for specific detection of the bacteria. Silver-incorporated vancomycin-modified mesoporous silica nanoparticles (MSNs@Van@Ag NPs) were designed for detection and treatment of MRSA bacteria. Mesoporous silica nanoparticles (MSNs) were synthesized through the template method, modified with vancomycin, and finally incorporated with silver nanoparticles (Ag NPs). The MSNs@Van@Ag NPs with a homogenously spherical shape, average size of 50-100 nm, surface area of 955.8 m2/g, and thermal stability up to 200°C were successfully characterized. The amount of Ag incorporated into the MSNs@Van@Ag was calculated at 3.9 ppm and the release amount of Ag was received at 2.92 ppm (75%) after 100 h. The in vitro antibacterial susceptibility test showed the MIC of 100 μg mL-1 for MSNs@Van and 50 μg mL-1 for MSNs@Van@Ag, showing in vitro enhanced effect of Ag and vancomycin in the bactericidal process. An in vivo acute pneumonia model was performed and biochemical assays and pathological studies confirmed the nanomedicine's short-term safety for in vivo application. Cytokine assay using ELISA showed that MSN@Van@Ag causes a reduction of pro-inflammatory cytokines and bacterial proliferation leading to alleviation of inflammatory response.

Progress in Treatment and Diagnostics of Infectious Disease with Polymers

In this era of advanced technology and innovation, infectious diseases still cause significant morbidity and mortality, which need to be addressed. Despite overwhelming success in the development of vaccines, transmittable diseases such as tuberculosis and AIDS remain unprotected, and the treatment is challenging due to frequent mutations of the pathogens. Formulations of new or existing drugs with polymeric materials have been explored as a promising new approach. Variations in shape, size, surface charge, internal morphology, and functionalization position polymer particles as a revolutionary material in healthcare. Here, an overview is provided of major diseases along with statistics on infection and death rates, focusing on polymer-based treatments and modes of action. Key issues are discussed in this review pertaining to current challenges and future perspectives.

Anti-Obesity Drug Delivery Systems: Recent Progress and Challenges

Obesity has reached an epidemic proportion in the last thirty years, and it is recognized as a major health issue in modern society now with the possibility of serious social and economic consequences. By the year 2030, nearly 60% of the global population may be obese or overweight, which emphasizes a need for novel obesity treatments. Various traditional approaches, such as pharmacotherapy and bariatric surgery, have been utilized in clinical settings to treat obesity. However, these methods frequently show the possibility of side effects while remaining ineffective. There is, therefore, an urgent need for alternative obesity treatments with improved efficacy and specificity. Polymeric materials and chemical strategies are employed in emerging drug delivery systems (DDSs) to enhance therapy effectiveness and specificity by stabilizing and controlling the release of active molecules such as natural ingredients. Designing DDSs is currently a top priority research objective with an eye towards creating obesity treatment approaches. In reality, the most recent trends in the literature demonstrate that there are not enough in-depth reviews that emphasize the current knowledge based on the creation and design of DDSs for obesity treatment. It is also observed in the existing literature that a complex interplay of different physical and chemical parameters must be considered carefully to determine the effectiveness of the DDSs, including microneedles, for obesity treatment. Additionally, it is observed that these properties depend on how the DDS is synthesized. Although many studies are at the animal-study stage, the use of more advanced DDS techniques would significantly enhance the development of safe and efficient treatment approaches for obese people in the future. Considering these, this review provides an overview of the current anti-obesity treatment approaches as well as the conventional anti-obesity therapeutics. The article aims to conduct an in-depth discussion on the current trends in obesity treatment approaches. Filling in this knowledge gap will lead to a greater understanding of the safest ways to manage obesity.

A Water-Soluble Polymer-Lumefantrine Conjugate for the Intravenous Treatment of Severe Malaria

Uncomplicated malaria is effectively treated with oral artemisinin-based combination therapy (ACT). Yet, there is an unmet clinical need for the intravenous treatment of the more fatal severe malaria. There is no combination intravenous therapy for uncomplicated due to the nonavailability of a water-soluble partner drug for the artemisinin, artesunate. The currently available treatment is a two-part regimen split into an intravenous artesunate followed by the conventional oral ACT . In a novel application of polymer therapeutics, the aqueous insoluble antimalarial lumefantrine is conjugated to a carrier polymer to create a new water-soluble chemical entity suitable for intravenous administration in a clinically relevant formulation . The conjugate is characterized by spectroscopic and analytical techniques, and the aqueous solubility of lumefantrine is determined to have increased by three orders of magnitude. Pharmacokinetic studies in mice indicate that there is a significant plasma release of lumefantrine and production its metabolite desbutyl-lumefantrine (area under the curve of metabolite is ≈10% that of the parent). In a Plasmodium falciparum malaria mouse model, parasitemia clearance is 50% higher than that of reference unconjugated lumefantrine. The polymer-lumefantrine shows potential for entering the clinic to meet the need for a one-course combination treatment for severe malaria.

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.

Stimuli-Responsive Poly(aspartamide) Derivatives and Their Applications as Drug Carriers

Poly(aspartamide) derivatives, one kind of amino acid-based polymers with excellent biocompatibility and biodegradability, meet the key requirements for application in various areas of biomedicine. Poly(aspartamide) derivatives with stimuli-responsiveness can usually respond to external stimuli to change their chemical or physical properties. Using external stimuli such as temperature and pH as switches, these smart poly(aspartamide) derivatives can be used for convenient drug loading and controlled release. Here, we review the synthesis strategies for preparing these stimuli-responsive poly(aspartamide) derivatives and the latest developments in their applications as drug carriers.

Nanobiotechnological modules as molecular target tracker for the treatment and prevention of malaria: options and opportunity

Malaria is one of the major infectious diseases that remains a constant challenge to human being mainly due to the emergence of drug-resistant strains of parasite and also the availability of drugs, which are non-specific for their pharmacodynamic activity and known to be associated with multiple side effects. The disease has acquired endemic proportions in tropical countries where the hygienic conditions are not satisfactory while the environmental conditions favor the proliferation of parasite and its transmission, particularly through the female anopheles. It is obvious that to square up the problems, there is a need for designing and development of more effective drugs, which can combat the drug-resistant strains of the parasite. Molecular biology of the parasite and its homing into host cellular tropics provide multiple drug targets that could judiciously be considered for engineering and designing of new generation antimalarial drugs and also drug delivery systems. Though the recent reports document that against malaria parasite the vaccine could be developed, nevertheless, due to smart mutational change overs by the parasite, it is able to bypass the immune surveillance. The developed vaccine therefore failed to assure absolute protection against the malarial infection. In the conventional mode of treatment antimalarial drugs, the dose and dosage regimen that is followed at large crops up the contraindicative manifestations, and hence compromising the effective treatment. The emerging trends and new updates in contemporary biological sciences, material sciences, and drug delivery domain have enabled us with the availability of a multitude of mode and modules which could plunge upon the nanotechnology in particular to treat this challenging infection. The nanotechnology-based option may be tuned or customized as per the requirements to mark and target i.e. the infected RBCs, for targeted drug delivery.

Recent advances in targeting malaria with nanotechnology-based drug carriers

Malaria, as one of the most common human infectious diseases, remains the greatest global health concern, since approximately 3.5 billion people around the world, especially those in subtropical areas, are at the risk of being infected by malaria. Due to the emergence and spread of drug resistance to the current antimalarials, malaria-related mortality and incidence rates have recently increased. To overcome the aforementioned obstacles, nano-vehicles based on biodegradable, natural, and non-toxic polymers have been developed. Accordingly, these systems are considered as a potential drug vehicle, which due to their unique properties such as the excellent safety profile, good biocompatibility, tunable structure, diversity, and the presence of functional groups within the polymer structure, could facilitate covalent attachment of targeting moieties and antimalarials to the polymeric nano-vehicles. In this review, we highlighted some recent developments of liposomes as unique nanoscale drug delivery vehicles and several polymeric nanovehicles, including hydrogels, dendrimers, self-assembled micelles, and polymer-drug conjugates for the effective delivery of antimalarials.

The key role of the drug self-aggregation ability to obtain optimal nanocarriers based on aromatic-aromatic drug-polymer interactions

The efficient association and controlled release of hydrophilic and aromatic low molecular-weight drugs (HALMD) still remains a challenge due to their relatively weak interactions with excipients and strong affinity to water. Considering that a wide variety of drugs to treat chronic diseases are HALMD, their inclusion in polymeric nanoparticles (NPs) constitutes an attractive possibility by providing to these drugs with controllable physiochemical properties, preventing crisis episodes, decreasing dose-dependent side effects and promoting therapeutic adhesiveness. However, the strong interaction of HALMD with the aqueous medium jeopardizes their encapsulation and controlled release. In this work, the role of the self-assembly tendency of HALMD on their association with the aromatic excipient poly(sodium 4-styrensulfonate) (PSS) to form NPs is studied. For this aim, the widely used drugs amitriptyline (AMT), promethazine (PMZ), and chlorpheniramine (CPM) are selected due to their well described critical aggregation concentration (cac) (36 mM for AMT, 36 mM for PMZ, and 69.5 mM for CPM). These drugs undergo aromatic-aromatic interactions with the polymer, which stabilize their mutual binding, as seen by NMR. The simple mixing of solutions of opposite charged molecules (drug + PSS) allowed obtaining NPs. Importantly, comparing the three drugs, the formation of NPs occurred at significantly lower absolute concentration and significantly lower drug/polymer ratio as the cac takes lower values, indicating a stronger binding to the polymer, as also deduced from the respective drug/polymer dissociation constant values. In addition, the number of formed NPs is similar for all formulations, even though a much lower concentration of the drug and polymer is present in systems comprising lower cac. The obtained NPs are spheroidal and present size between 100 and 160 nm, low polydispersity (≤0.3) and negative zeta potential (from -30 to -60 mV). The association efficiency reaches values ≥ 83% and drug loading could achieve values up to 68% (never evidenced before for systems comprising HALMD). In addition, drug release studies are also significantly influenced by cac, providing more prolonged release for AMT and PMZ (lower cac), whose delivery profiles adjust to the Korsmeyer-Peppas equation. As a novelty of this work, a synergic contribution of drug self-association tendency and aromatic-aromatic interaction between the drug and polymers is highlighted, a fact that could be crucial for the rational design and development of efficient drug delivery systems.

Composite P(3HB-3HV)-CS Spheres for Enhanced Antibiotic Efficiency

Natural-derived biopolymers are suitable candidates for developing specific and selective performance-enhanced antimicrobial formulations. Composite polymeric particles based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and chitosan, P(3HB-3HV)-CS, are herein proposed as biocompatible and biodegradable delivery systems for bioproduced antibiotics: bacitracin (Bac), neomycin (Neo) and kanamycin (Kan). The stimuli-responsive spheres proved efficient platforms for boosting the antibiotic efficiency and antibacterial susceptibility, as evidenced against Gram-positive and Gram-negative strains. Absent or reduced proinflammatory effects were evidenced on macrophages in the case of Bac-/Neo- and Kan-loaded spheres, respectively. Moreover, these systems showed superior ability to sustain and promote the proliferation of dermal fibroblasts, as well as to preserve their ultrastructure (membrane and cytoskeleton integrity) and to exhibit anti-oxidant activity. The antibiotic-loaded P(3HB-3HV)-CS spheres proved efficient alternatives for antibacterial strategies.

The Therapeutic Efficacy of Dendrimer and Micelle Formulations for Breast Cancer Treatment

Breast cancer is among the most common types of cancer in women and it is the cause of a high rate of mortality globally. The use of anticancer drugs is the standard treatment approach used for this type of cancer. However, most of these drugs are limited by multi-drug resistance, drug toxicity, poor drug bioavailability, low water solubility, poor pharmacokinetics, etc. To overcome multi-drug resistance, combinations of two or more anticancer drugs are used. However, the combination of two or more anticancer drugs produce toxic side effects. Micelles and dendrimers are promising drug delivery systems that can overcome the limitations associated with the currently used anticancer drugs. They have the capability to overcome drug resistance, reduce drug toxicity, improve the drug solubility and bioavailability. Different classes of anticancer drugs have been loaded into micelles and dendrimers, resulting in targeted drug delivery, sustained drug release mechanism, increased cellular uptake, reduced toxic side effects of the loaded drugs with enhanced anticancer activity in vitro and in vivo. This review article reports the biological outcomes of dendrimers and micelles loaded with different known anticancer agents on breast cancer in vitro and in vivo.

Nanoparticles Formulations of Artemisinin and Derivatives as Potential Therapeutics for the Treatment of Cancer, Leishmaniasis and Malaria

Cancer, malaria, and leishmaniasis remain the deadly diseases around the world although several strategies of treatment have been developed. However, most of the drugs used to treat the aforementioned diseases suffer from several pharmacological limitations such as poor pharmacokinetics, toxicity, drug resistance, poor bioavailability and water solubility. Artemisinin and its derivatives are antimalarial drugs. However, they also exhibit anticancer and antileishmanial activity. They have been evaluated as potential anticancer and antileishmanial drugs but their use is also limited by their poor water solubility and poor bioavailability. To overcome the aforementioned limitations associated with artemisinin and its derivatives used for the treatment of these diseases, they have been incorporated into nanoparticles. Several researchers incorporated this class of drugs into nanoparticles resulting in enhanced therapeutic outcomes. Their potential efficacy for the treatment of parasitic infections such as malaria and leishmaniasis and chronic diseases such as cancer has been reported. This review article will be focused on the nanoparticles formulations of artemisinin and derivatives for the treatment of cancer, malaria, and leishmaniasis and the biological outcomes (in vitro and in vivo).

Efficacy of Polymer-Based Nanocarriers for Co-Delivery of Curcumin and Selected Anticancer Drugs

Cancer remains a heavy health burden resulting in a high rate of mortality around the world. The presently used anticancer drugs suffer from several shortcomings, such as drug toxicity, poor biodegradability and bioavailability, and poor water solubility and drug resistance. Cancer is treated effectively by combination therapy whereby two or more anticancer drugs are employed. Most of the combination chemotherapies result in a synergistic effect and overcome drug resistance. Furthermore, the design of polymer-based nanocarriers for combination therapy has been reported by several researchers to result in promising therapeutic outcomes in cancer treatment. Curcumin exhibits good anticancer activity but its poor bioavailability has resulted in its incorporation into several polymer-based nanocarriers resulting in good biological outcomes. Furthermore, the incorporation of curcumin together with other anticancer drugs have been reported to result in excellent therapeutic outcomes in vivo and in vitro. Due to the potential of polymer-based nanocarriers, this review article will be focused on the design of polymer-based nanocarriers loaded with curcumin together with other anticancer drugs.

Polymer-Drug Conjugate, a Potential Therapeutic to Combat Breast and Lung Cancer

Cancer is a chronic disease that is responsible for the high death rate, globally. The administration of anticancer drugs is one crucial approach that is employed for the treatment of cancer, although its therapeutic status is not presently satisfactory. The anticancer drugs are limited pharmacologically, resulting from the serious side effects, which could be life-threatening. Polymer drug conjugates, nano-based drug delivery systems can be utilized to protect normal body tissues from the adverse side effects of anticancer drugs and also to overcome drug resistance. They transport therapeutic agents to the target cell/tissue. This review article is based on the therapeutic outcomes of polymer-drug conjugates against breast and lung cancer.

Synthesis, physicochemical characterization, toxicity and efficacy of a PEG conjugate and a hybrid PEG conjugate nanoparticle formulation of the antibiotic moxifloxacin

Moxifloxacin was conjugated to polyethylene glycol to segregate host cell toxicity from antimicrobial activity. The conjugate was then encapsulated into a polycaprolactone nanoparticle to assist the simultaneous delivery of multiple drugs to the site of microbial infection.