Breaking the barricade of oral chemotherapy through polysaccharide nanocarrier

Advances in Oral Biomacromolecule Therapies for Metabolic Diseases

Metabolic diseases like obesity and diabetes are on the rise, and therapies with biomacromolecules (such as proteins, peptides, antibodies, and oligonucleotides) play a crucial role in their treatment. However, these drugs are traditionally injected. For patients with chronic diseases (e.g., metabolic diseases), long-term injections are accompanied by inconvenience and low compliance. Oral administration is preferred, but the delivery of biomacromolecules is challenging due to gastrointestinal barriers. In this article, we introduce the available biomacromolecule drugs for the treatment of metabolic diseases. The gastrointestinal barriers to oral drug delivery and strategies to overcome these barriers are also explored. We then discuss strategies for alleviating metabolic defects, including glucose metabolism, lipid metabolism, and energy metabolism, with oral biomacromolecules such as insulin, glucagon-like peptide-1 receptor agonists, proprotein convertase subtilisin/kexin type 9 inhibitors, fibroblast growth factor 21 analogues, and peptide YY analogues.

Sweeten the pill: Multi-faceted polysaccharide-based carriers for colorectal cancer treatment

Colorectal cancer (CRC) ranks as the second deadliest cancer globally and the third most common malignant tumor. While surgery remains the primary treatment for CRC, alternative therapies such as chemotherapy, molecular targeted therapy, and immunotherapy are also commonly used. The significant side effects and toxicity of conventional drugs drive the search for novel targeted therapies, including the design of advanced drug delivery systems. Polysaccharide-based biopolymers, with their low toxicity, non-immunogenic behavior, synergistic interactions with other biopolymers, and tissue and cell compatibility, emerge as excellent drug carriers for this application. This review aims to provide an in-depth overview of recent advancements in developing polysaccharide-based biopolymeric carriers for anticancer compounds in the treatment of CRC. We highlight the multifunctional nature of polysaccharides, showcasing their potential as standalone drug carriers or as integral components of intelligent robotic devices for biomedical therapeutic applications. In addition to exploring the opportunities for using carbohydrate polymers in CRC treatment, we address the challenges and failures that may limit their applicability in biomedical research, as well as summarize the recent preclinical and clinical trials, resulting in several commercialization attempts. This comprehensive overview critically summarizes the potential of polysaccharide-based biomaterials in CRC treatment.

Functional properties and molecular docking of different nanoparticles with ROS-sensitive phenylboronylated chitosan as the carrier

OBJECTIVE

To prepare chitosan-loaded nanoparticles (NPs) that enhance the oral bioavailability of puerarin (Pur) and render it responsive to reactive oxygen species (ROS).

SIGNIFICANCE

This research makes substantial progress towards the theory of intelligent drug delivery, offering a new reference for combining Pur with other natural medicinal active ingredients.

METHODS

The acylation reaction between chitosan and ROS-sensitive 3-carboxyphenylboronic acid (PBA) was used to synthesise ROS-sensitive phenylboronylated chitosan (PBACS). Subsequently, PBACS-PBA-Pur-NPs and PBACS-TPP-Pur-NPs were prepared via ion gelation after the addition of PBA and sodium tripolyphosphate(TPP), respectively. The physicochemical and functional properties of both NPs were compared, and their differences were preliminarily studied through molecular docking.

RESULTS

Reactive oxygen species-sensitive PBACS was successfully synthesised. Of the two NPs prepared, PBACS-TPP-Pur-NPs had a size of 127.2 ± 0.80 nm, polydispersity index (PDI) of 0.129 ± 0.0008, and an encapsulation rate of 95.75 ± 0.387 %, whereas PBACS-PBA-Pur-NPs had a size of 149.8 ± 0.1414 nm, PDI of 0.389 ± 0.0012, and an encapsulation rate of 91.77 ± 0.279 %. The micromorphology of the PBACS-TPP-Pur-NPs exhibited better physical properties. However, PBACS-PBA-Pur-NPs demonstrated a faster in vitro release and more significant in vitro anti-inflammatory effects. Pharmacokinetically, the AUC0-24, Tmax, and Cmax of PBACS-PBA-Pur-NPs were 3.485, 2.117, and 3.339 times higher, respectively, than those of Pur. The AUC0-24, Tmax, and Cmax of PBACS-TPP-Pur-NPs were 2.41, 1.33, and 2.03 times higher, respectively, than those of Pur. Molecular simulation revealed that the binding energy of PBACS-PBA-Pur -NPs was approximately -4.34 kcal/mol and that of PBACS-TPP-Pur-NPs was even lower, approximately -5.93 kcal/mol, suggesting that the NPs prepared with TPP are more densely packed than those designed with PBA, resulting in slower and reduced drug release.

CONCLUSION

The NPs constructed in this study effectively reduced inflammatory factors at the disease site, providing a theoretical and experimental basis for the application of nano drugs in inflammatory disease models. In addition, the molecular docking study of the two NPs offered insights into the relationship between the release and structure of subsequent nano drugs.

Anti-liver cancer effects and mechanisms and its application in nano DDS of polysaccharides: A review

Liver cancer is the third leading cause of cancer death, with high incidence and poor treatment effect. In recent years, polysaccharides have attracted more and more attention in the research field of anti-liver cancer because of their high efficiency, low toxicity, good biocompatibility, wide sources and low cost. Polysaccharides have been proven to have good anti-liver cancer activity. In this paper, the pathways and molecular mechanisms of polysaccharides against liver cancer were reviewed in detail. Polysaccharides exert anti-liver cancer activity by blocking cell cycle, inducing apoptosis, regulating immunity, inhibiting cancer cell metastasis, inhibiting tumor angiogenesis and so on. The primary structure and chain conformation of polysaccharides have an important influence on their anti-liver cancer activity. Structural modification enhanced the anti-liver cancer activity of polysaccharides. Polysaccharides have good attenuated and synergistic effects on chemotherapy drugs. Polysaccharides can be used as functional carriers to construct intelligent nano drug delivery systems (DDS) targeting liver cancer. This review can provide theoretical support for the further development and application of polysaccharides in the field of anti-liver cancer, and provide theoretical reference and clues for relevant researchers in food, nutrition, medicine and other fields.

Enteral Route Nanomedicine for Cancer Therapy

With the in-depth knowledge of the pathological and physiological characteristics of the intestinal barrier-portal vein/intestinal lymphatic vessels-systemic circulation axis, oral targeted drug delivery is frequently being renewed. With many advantages, such as high safety, convenient administration, and good patient compliance, many researchers have begun to explore targeted drug delivery from intravenous injections to oral administration. Over the past few decades, the fields of materials science and nanomedicine have produced various drug delivery platforms that hold great potential in overcoming the multiple barriers associated with oral drug delivery. However, the oral transport of particles into the systemic circulation is extremely difficult due to immune rejection and biochemical invasion in the intestine, which limits absorption and entry into the bloodstream. The feasibility of the oral delivery of targeted drugs to sites outside the gastrointestinal tract (GIT) is unknown. This article reviews the biological barriers to drug absorption, the in vivo fate and transport mechanisms of drug carriers, the theoretical basis for oral administration, and the impact of carrier structural evolution on oral administration to achieve this goal. Finally, this article reviews the characteristics of different nano-delivery systems that can enhance the bioavailability of oral therapeutics and highlights their applications in the efficient creation of oral anticancer nanomedicines.

Resveratrol-loaded sulfated Hericium erinaceus β-glucan-chitosan nanoparticles: Preparation, characterization and synergistic anti-inflammatory effects

Resveratrol (RES) is a natural polyphenol with excellent biological activity. But the poor stability and bioavailability of RES severely limit its application. Thus, the resveratrol-loaded sulfated Hericium erinaceus β-glucan-chitosan nanoparticles (DS-CS-RES NPs) were prepared using electrostatic self-assembly to solve these problems in this study. The structure of DS-CS-RES NPs was spherical or sub spherical shape with small average particle size (191.07 nm), which was characterized by FT-IR, FS, XRD and TEM. DS-CS-RES NPs exhibited good stability and RES had a sustainable release from the nanoparticles in gastrointestinal digestion. Meanwhile, DS-CS-RES NPs could improve the inflammatory injury of LPS stimulated RAW264.7 macrophages by inhibiting the production of NO, IL-1β, IL-6 and TNF-α. Furthermore, DS-CS-RES NPs had strong anti-inflammatory activity by regulating protein levels of NF-κB p65, STAT1 and TLR4 through NF-κB and JAK-STAT1 signaling pathway in vitro, and sulfated H. erinaceus β-glucan-chitosan nanoparticle (DS-CS NPs) and RES had synergistic anti-inflammatory effect. Overall, DS-CS NPs can serve as a potential green and safe functional carrier for encapsulating resveratrol, which can improve its anti-inflammatory activity. This work may be conducive to the development of functional carrier for encapsulating RES and applications of hydrophobic active molecules in functional foods or medicines.

Oral peptide therapeutics for diabetes treatment: State-of-the-art and future perspectives

Diabetes, characterized by hyperglycemia, is a major cause of death and disability worldwide. Peptides, such as insulin and glucagon-like peptide-1 (GLP-1) analogs, have shown promise as treatments for diabetes due to their ability to mimic or enhance insulin's actions in the body. Compared to subcutaneous injection, oral administration of anti-diabetic peptides is a preferred approach. However, biological barriers significantly reduce the efficacy of oral peptide therapeutics. Recent advancements in drug delivery systems and formulation techniques have greatly improved the oral delivery of peptide therapeutics and their efficacy in treating diabetes. This review will highlight (1) the benefits of oral anti-diabetic peptide therapeutics; (2) the biological barriers for oral peptide delivery, including pH and enzyme degradation, intestinal mucosa barrier, and biodistribution barrier; (3) the delivery platforms to overcome these biological barriers. Additionally, the review will discuss the prospects in this field. The information provided in this review will serve as a valuable guide for future developments in oral anti-diabetic peptide therapeutics.

Potential therapeutic target for polysaccharide inhibition of colon cancer progression

In recent years, colon cancer has become one of the most common malignant tumors worldwide, posing a great threat to human health. Studies have shown that natural polysaccharides have rich biological activities and medicinal value, such as anti-inflammatory, anti-cancer, anti-oxidation, and immune-enhancing effects, especially with potential anti-colon cancer mechanisms. Natural polysaccharides can not only protect and enhance the homeostasis of the intestinal environment but also exert a direct inhibition effect on cancer cells, making it a promising strategy for treating colon cancer. Preliminary clinical experiments have demonstrated that oral administration of low and high doses of citrus pectin polysaccharides can reduce tumor volume in mice by 38% (p < 0.02) and 70% (p < 0.001), respectively. These results are encouraging. However, there are relatively few clinical studies on the effectiveness of polysaccharide therapy for colon cancer, and ensuring the effective bioavailability of polysaccharides in the body remains a challenge. In this article, we elucidate the impact of the physicochemical factors of polysaccharides on their anticancer effects and then reveal the anti-tumor effects and mechanisms of natural polysaccharides on colon cancer. Finally, we emphasize the challenges of using polysaccharides in the treatment of colon cancer and discuss future applications.

Gastrointestinal metabolism characteristics and mechanism of a polysaccharide from Grifola frondosa

Grifola frondosa polysaccharide (GFP) is mainly composed of α-1,4 glycosidic bonds and possesses multiple pharmacological activities. However, the absence of pharmacokinetic studies has limited its further development and utilization. Herein, GFP was labeled with 5-DTAF (FGFP) and cyanine 5.5 amine (GFP-Cy5.5) to investigate its gastrointestinal metabolism characteristics and mechanism. Significant distributions of the polysaccharide in the liver and kidneys were observed by near infrared imaging. To investigate the specific distribution form of the polysaccharide, in vitro digestion models were constructed and revealed that FGFP was degraded in saliva and rat small intestine extract. The metabolites were detected in the stomach and small intestine, followed by further degradation in the distal intestine in the in vivo experiment. Subsequent investigations showed that α-amylase was involved in the gastrointestinal degradation of GFP, and its metabolite finally entered the kidneys, where it was excreted directly with urine.

Preparation, identification, and application of PEG/ZIF-8@ Dendrobium huoshanense polysaccharide as an adjuvant to enhance immune responses

Zeolitic imidazolate framework-8 (ZIF-8) nanoparticles loaded with polysaccharides are excellent drug-delivery carriers with high loading capacity and pH sensitivity. This study describes the one-step encapsulation of Dendrobium huoshanense polysaccharides (DHP) in ZIF-8. The resultant PEG6000/ZIF-8@DHP complex exhibited drug release properties in acidic microenvironments, possessed water solubility, demonstrated high drug loading capacity, and displayed effective encapsulation. The effects of PEG6000/ZIF-8@ DHP administration on immunoregulation, antioxidant activities, and resistance against Aeromonas veronii in channel catfish were assessed. The study revealed that the PEG6000/ZIF-8@DHP complex stimulated cellular proliferation and phagocytosis, while also inducing the production of cytokines and nitric oxide. Additionally, the complex exhibited improved antioxidant properties and increased serum lysozyme and alkaline phosphatase activities. PEG6000/ZIF-8@DHP exhibited efficacy in vivo against Aeromonas veronii infection. These results indicate that PEG6000/ZIF-8@DHP is an efficient immunostimulant and vaccine adjuvant for enhancing immunity in channel catfish.

Facile Fabrication of Dual-Activatable Gastrointestinal-Based Nanocarriers for Safe Delivery and Controlled Release of Methotrexate

Colon cancer is emerging as one of the most common cancers worldwide, ranking in the top three in morbidity and mortality. Oral methotrexate (MTX) has been employed as a first-line treatment for various cancers, such as colon, breast, and lung cancer. However, the complexity and particularity of the gastrointestinal microenvironment and the limitations of MTX itself, including severe adverse effects and instability, are the main obstacles to the safe delivery of MTX to colon tumor sites. Herein, an innovative oral administrated anticancer therapeutic MTX@Am7CD/SDS NPs equipped with both pH and temperature sensitivity, which could effectively prevent MTX@Am7CD/SDS NPs from being degraded in the acidic environment mimicking the stomach and small intestine, thus harboring the potential to accumulate at the site of colon lesions and further release intestinal drug under mild conditions. In cellular assays, compared with free MTX, MTX@Am7CD/SDS NPs showed a favorable tumor inhibition effect on three tumor cell lines, as well as excellent cell uptake and apoptosis-inducing effect on SW480 cells. Therefore, this work provides a feasible solution for the safe use of MTX in the treatment of colon cancer and even other intestinal diseases.

A Gellan Gum/Sodium Alginate-based gastric-protective hydrogel loaded with a combined herbal extract consisting of Panax notoginseng, Bletilla striata and Dendrobium officinale

One Chinese herbal combination consisting of Panax notoginseng, Bletilla striata and Dendrobium officinale (PBD) is an effective Traditional Chinese Medicine (TCM) prescription and is widely used in clinics to treat gastric ulcers due to their safety and effectiveness compared with chemical agents, such as aspirin and omeprazole. Herein, an in situ forming gel (ISFG) based on Gellan Gum (GG) and Sodium Alginate (SA) was designed to deliver extracts of PBD prescription (EPBDP). The central composite design optimized prescription dosage was 0.1 % w/v of GG and 0.5 % w/v of SA. Gels prepared with this formulation demonstrated outstanding fluidity and instantaneous gel formation. In vitro release data showed that sustained drug release occurred in the gel, and the gel was pH-sensitive. The rheological tests confirmed the formation of stable gel, which exhibited strong viscosity and elasticity. In vitro adhesion assays revealed that the gel had strong gastric mucosal adhesion, while in vivo residual rate experiments of active ingredients revealed that the gel might greatly improve the gastric retention of active ingredients. Animal studies demonstrated that the gel was effective in treating gastric ulcers. Hence, the results of the study show that EPBDP-ISFG, a highly pH-sensitive sustained-release system, is effective.

Recent Advances in Kaolinite Nanoclay as Drug Carrier for Bioapplications: A Review

Advanced functional two-dimensional (2D) nanomaterials offer unique advantages in drug delivery systems for disease treatment. Kaolinite (Kaol), a nanoclay mineral, is a natural 2D nanomaterial because of its layered silicate structure with nanoscale layer spacing. Recently, Kaol nanoclay is used as a carrier for controlled drug release and improved drug dissolution owing to its advantageous properties such as surface charge, strong biocompatibility, and naturally layered structure, making it an essential development direction for nanoclay-based drug carriers. This review outlines the main physicochemical characteristics of Kaol and the modification methods used for its application in biomedicine. The safety and biocompatibility of Kaol are addressed, and details of the application of Kaol as a drug delivery nanomaterial in antibacterial, anti-inflammatory, and anticancer treatment are discussed. Furthermore, the challenges and prospects of Kaol-based drug delivery nanomaterials in biomedicine are discussed. This review recommends directions for the further development of Kaol nanocarriers by improving their physicochemical properties and expanding the bioapplication range of Kaol.

Dextran-Cholesterol Carrier Encapsulated Efficient Photosensitizer for the Photodynamic Killing of Cancer Cells

Selective photodynamic therapy (PDT) for cancer cells is more efficient and much safer. Most selective PDTs are realized by antigene-biomarker or peptide-biomarker interactions. Here, we modified dextran with hydrophobic cholesterol as a photosensitizer carrier to selectively target cancer cells, including colon cancer cells, and fulfilled selective PDT. The photosensitizer was designed with regular Aggregation-Induced Emission (AIE) units, including triphenylamine and 2-(3-cyano-4,5,5-trimethylfuran-2-ylidene)propanedinitrile. The AIE units can help to decrease the quenching effect in the aggregate state. The efficiency of the photosensitizer is further improved via the heavy atom effect after bromination modification. We found that the obtained photosensitizer nanoparticles could selectively target and ablate cancer cells after encapsulation into the dextran-cholesterol carrier. This study indicates that the polysaccharide-based carrier may have potential for cancer-targeting therapy beyond expectations.

Self-nanoemulsifying drug delivery systems (SNEDDS) of anti-cancer drugs: a multifaceted nanoplatform for the enhancement of oral bioavailability

OBJECTIVE

A significant problem faced by the health care industry today is that though there are numerous drugs available to tackle diseases like cancer, their intrinsic properties make it difficult to be delivered to patients in a feasible manner. One of the key players that have helped researchers overcome poor solubility and permeability of drugs is Nanotechnology, this article further iterates on the same.

SIGNIFICANCE

Nanotechnology is used as an umbrella term in pharmaceutics and describes under it multiple technologies. Upcoming nanotechnology is a Self Nanoemulsifying System which is considered to be a futuristic delivery system both due to its scientific simplicity and relative ease of patient delivery.

METHODS

Self-Nano Emulsifying Drug Delivery Systems (SNEDDS) are homogenous lipidic concoctions containing the drug solubilized in the oil phase and surfactants. The choice of components depends on the physicochemical properties of the drugs, the solubilization capability of oils and the physiological fate of the drug. The article contains further details of various methodologies that have been adopted by scientists to formulate and optimize such systems in order to make anticancer drugs orally deliverable.

RESULTS

The results that have been generated by scientists across the globe have been summarized in the article and all of the data supports the claim that SNEDDS significantly enhance the solubility and bioavailability of hydrophobic anticancer drugs.

CONCLUSIONS

This article mainly provides the application of SNEDDS in cancer therapy and concludes to provide a step for the oral administration of several BCS class II and IV anticancer drugs.

Ligand-modified nanocarriers for oral drug delivery: Challenges, rational design, and applications

Ligand-modified nanocarriers (LMNCs) specific to their targets have attracted increasing interest for enhanced oral drug delivery in recent decades. Although the design of LMNCs for enhanced endocytosis and improved exposure of the loaded drugs through the oral route has received abundant attention, it remains unclear how the design influences their transcellular process, especially the key factors affecting their functions. This review discusses the extracellular and cellular barriers to orally administered LMNCs in the gastrointestinal (GI) tract and new discoveries regarding the GI protein corona and the sequential transport barriers that impede the preplanned movements of LMNCs after oral administration. Furthermore, innovative progress in considering key factors (including target selection, ligand properties, and other important factors) in the rational design of LMNCs for oral drug delivery is presented. In particular, some factors that endow LMNCs with efficient transcytosis rather than only endocytosis are highlighted. Finally, the prospects of orally administered LMNCs in disease therapy for the enhanced oral/local bioavailability of active pharmaceutical ingredients, as well as emerging delivery routes, such as lymphatic drug delivery and systemic location-specific drug release based on oral transcellular LMNCs, are discussed.

CFNC, a neocryptolepine derivative, inhibited the growth of gastric cancer AGS cells by inhibiting PI3K/AKT signaling pathway

Gastric cancer is highly heterogeneous and there is still a lack of efficient, low-toxicity small molecule compounds for the treatment of gastric cancer. Natural products are important sources for the development of antitumor compounds. Therefore, it is promising strategy to find the lead compound of anti-gastric cancer agents by structural modification of natural products. The aim of this study was to synthesize a novel neocryptolepine derivative CFNC and explore its potential anti-gastric cancer effect and molecular mechanism. The MTT assay showed that the IC₅₀ of CFNC on AGS cells reached 148 nM. CFNC arrested AGS cells in the G2/M phase of the cell cycle. Furthermore, CFNC inhibited cell proliferation and migration, leading to the loss of membrane potential by causing mitochondrial dysfunction, which induced the apoptosis of AGS cells. Western blot assay suggested that CFNC could inhibit the expression of important proteins in the PI3K/AKT/mTOR signaling pathway. These results showed that CFNC exhibited strong cytotoxic activity in gastric cancer cell lines by regulating the PI3K/AKT/mTOR signaling pathway. Taken together, CFNC could be a promising lead compound for the clinical treatment of gastric cancer.

Structural Characterization and Hypoglycemic Activity of a Novel Pumpkin Peel Polysaccharide-Chromium(III) Complex

The aim of our study was to synthesize a pumpkin peel polysaccharide (PPP)-Cr(III) complex and investigate its hypoglycemic activity. Firstly, a novel PPP-Cr(III) complex with a Cr content of 23.77 mg/g was synthesized and characterized. Physicochemical characterization indicated that PPP-Cr(III) had some changes in chemical composition, monosaccharide composition, and morphological structure compared with PPP. The molecular weights of PPP-Cr(III) and PPP were 1.398 × 106 g/mol and 3.386 × 106 g/mol, respectively, showing a lower molecular weight after the introduction of Cr(III). Fourier transform infrared spectroscopy showed that a new characteristic absorption peak of Cr-O appeared at 534 cm-1 in PPP-Cr(III), indicating that Cr(III) was successfully complexed with PPP. Secondly, the hypoglycemic activity of PPP-Cr(III) based on α-glucosidase inhibitory and insulin resistance (IR)-HepG2 cells was evaluated. Compared with PPP, PPP-Cr(III) exhibited a more significantly α-glucosidase inhibitory activity. The IR-HepG2 cells confirmed an obvious increase in glucose consumption. Western blot analysis demonstrated that the treated IR-HepG2 cells were able to increase the protein levels of p-AMPK and p-GSK-3β, indicating that IR-HepG2 cells exerted hypoglycemic activity via the AMPK/GSK-3β signaling pathway. These results suggested that PPP-Cr(III) had good hypoglycemic activity, which could provide theoretical support for the development of novel hypoglycemic products.

Design, synthesis and biological evaluation of novel o-aminobenzamide derivatives as potential anti-gastric cancer agents in vitro and in vivo

Although gastric cancer has become a major public health problem, oral agents applied in clinics for gastric cancer therapy are scarce. Therefore, to explore new oral chemical entities with high efficiency and low toxicity, 41 o-aminobenzamide derivatives based on the scaffolds of MS-275 and SAHA were designed, synthesized, and evaluated for their anti-gastric cancer abilities in vitro and in vivo. Structure-activity relationships were discussed, leading to the identification of compounds F8 (IC₅₀ = 0.28 μM against HGC-27 cell) and T9 (IC₅₀ = 1.84 μM against HGC-27 cell) with improved cytotoxicity, anti-gastric cancer proliferation potency, induction of cell apoptosis and cell cycle arrest ability, inhibition of cell migration and invasion. What is worth mentioning is that compound F8 was more efficient and less toxic than the positive drug capecitabine in vivo on the HGC-27-xenograft model. Meanwhile, compound F8 exhibited suitable pharmacokinetic properties and less acute toxicity (LD₅₀ > 1000 mg/kg). Besides, western blotting analysis, IHC analysis, differentially expressed proteins analysis and ABPP experiment indicated that compound F8 could modulate molecular pathways involved in apoptosis and cell cycle progression. Consequently, compound F8 is a strong candidate for the development of human gastric cancer therapy.

Nanomedicine for increasing the oral bioavailability of cancer treatments

Abstract

Oral administration is an appealing route of delivering cancer treatments. However, the gastrointestinal tract is characterized by specific and efficient physical, chemical, and biological barriers that decrease the bioavailability of medications, including chemotherapeutics. In recent decades, the fields of material science and nanomedicine have generated several delivery platforms with high potential for overcoming multiple barriers associated to oral administration. This review describes the properties of several nanodelivery systems that improve the bioavailability of orally administered therapeutics, highlighting their advantages and disadvantages in generating successful anticancer oral nanomedicines.

Graphical Abstract

Repurposing of nifedipine loaded in situ ophthalmic gel as a novel approach for glaucoma treatment

Glaucoma is a chronic eye disease characterized by elevated intraocular pressure (IOP) which causes severe complications to the eyes and may lead to vision loss. The effective treatment of such diseases motivated the search for novel and unique drugs and delivery systems. It has been reported that, nifedipine (NF) is effective in reducing the elevated IOP due to vasodilatation of eye vascular smooth muscles. NF loaded thermo-sensitive in situ gels were prepared by the cold method using poloxamer 407 (P407) and hydroxypropyl methyl cellulose (HPMC) polymers adopting Box-Behnken experimental design. All the prepared formulae were tested for homogeneity, clarity, pH, isotonicity, gelling capacity, rheological behavior, in vitro drug release and were tested in vivo on rabbits. The prepared in situ gels were homogenous, transparent, having a pH ranged from 5 to 5.5 and undergo sol-gel transition within few seconds physiological temperature. The in situ gels showed sustained in vitro release of NF where about 76% of the loaded drug was released over 12 h. NF loaded in situ gels showed a 45.83 ± 2.91% reduction in the IOP, with no sign of toxicity or irritation to the eye in rabbits. The current investigations clarified the efficiency of this novel and unique NF loaded in situ gel for the control of the IOP compared to the conventional ophthalmic dosage forms.

Selenium release kinetics and mechanism from Cordyceps sinensis exopolysaccharide-selenium composite nanoparticles in simulated gastrointestinal conditions

This work investigated selenium (Se) release kinetics and mechanism from exopolysaccharide-selenium nanoparticles (EPS-SeNPs, Se/EPS = 1/20, 1/1 and 4/3) in simulated gastric (SGF) and intestinal fluids (SIF) using kinetics models of Zero order, First order, Higuchi, Hixson-Crowell and Korsmeyer-Peppas. EPS-SeNPs showed an increase in size from 80-125 nm to 250-320 nm and more ambiguous boundary after gastrointestinal digestion. Se/EPS ratio and pH had significant influence on Se release. Se release kinetics from EPS-SeNPs (Se/EPS = 1/1 and 4/3 in SGF) followed a classical Fickian diffusion, in contrast to an erosion governed by macromolecular chains relaxation for Se/EPS = 1/20 in SIF. Se release from EPS-SeNPs (Se/EPS = 1/1 and 4/3 in SIF) was well-fitted to Korsmeyer-Peppas model and followed a non-Fickian mechanism controlled by both diffusion and erosion. Additionally, EPS-SeNPs (Se/EPS = 1/20) showed a low Se release after SGF digestion, but a high release after SIF digestion, suggesting its application in controlled release of Se-enriched supplements for Se-deficiency treatment.

Protective effects of polysaccharides on cerebral ischemia: A mini-review of the mechanisms

Cerebral ischemia, a common cerebrovascular disease, is one of the great threats to human health. Nowadays, many drugs used in the treatment of cerebral ischemia such as clot busting drugs, antiplatelet drugs, and neuroprotective drugs have limits. It is urgent finding new effective treatments for the patients. Researches have confirmed that many kinds of polysaccharides from natural resources possess therapeutic effects on cerebral ischemia, but are still lack of a comprehensively understanding. In this paper, based on the pathophysiology of cerebral ischemic injury, we summarize the latest discoveries and advancements of 29 kinds of polysaccharides, focusing on their ameliorating effects on cerebral ischemia and the underlying mechanisms. Several mechanisms are involved, mainly including antioxidant activities, anti-inflammatory activities, regulating neuron apoptosis, as well as resisting nitrosative stress injury. Besides, polysaccharides show protective effects through certain signaling pathways including PI3K/Akt, MAPK, and NF-κB, PARP-1/AIF, JNK3/c-Jun/Fas-L, and Nrf2/HO-1 signaling pathways. The main goal of this mini-review is to emphasize the important roles of polysaccharides in attenuating cerebral ischemic injury through the elucidation of mechanisms.

Xyloglucan as green renewable biopolymer used in drug delivery and tissue engineering

Xyloglucan is a mucoadhesive polysaccharide which is extracted from the cell wall of vascular plants. Tamarind seeds are the abundant source of xyloglucan and commercially more popular. It is biocompatible, biodegradable, and nontoxic in nature. It is approved by the FDA for use as a food additive, stabilizing and thickening agent or gelling agent. Recently, many researchers are giving attention to xyloglucan for drug delivery through various routes and regeneration of the number of tissues. However, the findings of tissue regeneration and drug delivery in combination are not collected and represented in a simple and comprehensive way. The aim of this review is to find and represent these missing links. This review presents current researches on xyloglucan in drug delivery and regeneration of tissue.