Antitumor Efficacy and Toxicity of 5-Fluorouracil-Loaded Poly(Lactide Co-glycolide) Pellets

Gastrointestinal tumor-related perihepatic fluorouracil encapsulated lesions and liver metastases: a diagnostic imaging study based on contrast-enhanced computed tomography and magnetic resonance imaging

Background

Perihepatic fluorouracil encapsulated lesions (FELs) can result in potentially confusing computed tomography (CT) and magnetic resonance imaging (MRI) features in postoperative examinations of gastrointestinal tumors. This retrospective study aimed to summarize the typical imaging features of FELs and determine the best imaging modality to distinguish FELs from liver metastases for junior residents.

Methods

Patients with FELs who had undergone gastrointestinal tumor surgery in Tongji Hospital from January 2016 to June 2022 were evaluated. The imaging features of FELs were summarized by two senior radiologists. Contrast-enhanced CT (CECT) was used as the primary follow-up tool for postoperative gastrointestinal tumor patients. Patients with FELs and available CECT and MRI examinations were matched with patients with liver metastases based on gender and age and presented in chronological order in a 2:1 ratio. Different imaging modality combinations were used for further evaluation, including a CECT group (modality Ⅰ), CECT and nonenhanced MRI group (modality Ⅱ) and CECT with all MRI sequences group (modality Ⅲ). Subsequently, two junior residents blindly evaluated three groups following a 4-week interval based on a 5-point scale (1= definite benign lesion, 2= probable benign lesion, 3= indeterminate, 4= probable liver metastasis, 5= definite liver metastasis).

Results

Imaging features of 33 patients with 36 FELs were analyzed. CECT and dynamic contrast-enhanced MRI (DCE-MRI) showed no enhancement in most lesions. Additionally, 20 patients with FELs meeting the requirements were matched with 40 patients with liver metastases. The highest sensitivity, specificity, and consistency for identifying liver metastases were achieved using a combination of CECT and MRI encompassing all sequences yielded, including modality Ⅰ (reader 1: 72.0% and 17.4%; reader 2: 62.0% and 17.4%; kappa value 0.295), modality Ⅱ (reader 1: 88.0% and 8.7%; reader 2: 92.0% and 34.8%; kappa value 0.259), and modality Ⅲ (reader 1: 98.0% and 34.8%; reader 2: 92.0% and 39.1%; kappa value 0.680).

Conclusions

FELs are typically non-enhancing lesions. In our study, two junior residents could best distinguish FELs from liver metastases using CECT with all MRI sequences.

Biodegradable and removable implants for controlled drug delivery and release application

Conventional drug delivery route has several limitations such as hepatic first-pass metabolism, gastric issues, hypersensitivity reactions, etc. Additionally, such approaches are not found to be patient compliant, especially for chronic diseases. Conversely, implantable, polymeric drug delivery systems provide prolonged as well as controlled release of drug from the device implanted in the body. This editorial summarizes various types of implantable drug delivery systems along with their associated advantages and challenges. Additionally, recent advances in this field such as shape memory-based polymeric implants and 3-D printed implants are also discussed carefully and critically.

Theoretical investigation of Chitosan-Assisted Controlled Release of Digestive System Antitumor Drug Fluorouracil

5-Fluorouracil (5-FU) has been applied to treat pancreatic cancer, which is one of the most common types of digestive system tumors. However, due to poor tumor selectivity, 5-FU's therapeutic effect has certain limitations. 5-FU's activity and selectivity against tumor cells can be improved by chitosan assisted drug delivery systems. Understanding the atomic interaction mechanism between chitosan and 5-FU is important. In this work, the interactions between 5-FU and different types of chitosan were systematically investigated by using molecular dynamics (MD) simulation. Based on the radial distribution function and the free energy calculation, our results demonstrate that the functional groups of chitosan could greatly regulate the interaction behavior between chitosan and 5-FU. Moreover, 5-FU could gradually release from chitosan at a more acidic pH (tumor tissues) environment. These results revealed the underlying atomic interaction mechanism between 5-FU and chitosan at various pH levels, and may be helpful in the design of chitosan-based drug delivery systems.

Hot-Melt Extrusion: a Roadmap for Product Development

Hot-melt extrusion has found extensive application as a feasible pharmaceutical technological option over recent years. HME applications include solubility enhancement, taste masking, and sustained drug release. As bioavailability enhancement is a hot topic of today's science, one of the main applications of HME is centered on amorphous solid dispersions. This review describes the most significant aspects of HME technology and its use to prepare solid dispersions as a drug formulation strategy to enhance the solubility of poorly soluble drugs. It also addresses molecular and thermodynamic features critical for the physicochemical properties of these systems, mainly in what concerns miscibility and physical stability. Moreover, the importance of applying the Quality by Design philosophy in drug development is also discussed, as well as process analytical technologies in pharmaceutical HME monitoring, under the current standards of product development and regulatory guidance. Graphical Abstract.

Leveraging advances in chemistry to design biodegradable polymeric implants using chitosan and other biomaterials

The metamorphosis of biodegradable polymers in biomedical applications is an auspicious myriad of indagation. The utmost challenge in clinical conditions includes trauma, organs failure, soft and hard tissues, infection, cancer and inflammation, congenital disorders which are still not medicated efficiently. To overcome this bone of contention, proliferation in the concatenation of biodegradable materials for clinical applications has emerged as a silver bullet owing to eco-friendly, nontoxicity, exorbitant mechanical properties, cost efficiency, and degradability. Several bioimplants are designed and fabricated in a way to reabsorb or degrade inside the body after performing the specific function rather than eliminating the bioimplants. The objective of this comprehensive is to unfurl the anecdote of emerging biological polymers derived implants including silk, lignin, soy, collagen, gelatin, chitosan, alginate, starch, etc. by explicating the selection, fabrication, properties, and applications. Into the bargain, emphasis on the significant characteristics of current discernment and purview of nanotechnology integrated biopolymeric implants has also been expounded. This robust contrivance shed light on recent inclinations and evolution in tissue regeneration and targeting organs followed by precedency and fly in the ointment concerning biodegradable implants evolved by employing fringe benefits provided by 3D printing technology for building tissues or organs construct for implantation.

Basics to advances in nanotherapy of colorectal cancer

Colorectal cancer (CRC) is the third most common cancer existing across the globe. It begins with the formation of polyps leading to the development of metastasis, especially in advanced stage patients, who necessitate intensive chemotherapy that usually results in a poor response and high morbidity owing to multidrug resistance and severe untoward effects to the non-cancerous cells. Advancements in the targeted drug delivery permit the targeting of tumor cells without affecting the non-tumor cells. Various nanocarriers such as liposomes, polymeric nanoparticles, carbon nanotubes, micelles, and nanogels, etc. are being developed and explored for effective delivery of cytotoxic drugs to the target site thereby enhancing the drug distribution and bioavailability, simultaneously subduing the side effects. Moreover, immunotherapy for CRC is being explored for last few decades. Few clinical trials have even potentially benefited patients suffering from CRC, still immunotherapy persists merely an experimental alternative. Assessment of the ongoing and completed trials is to be warranted for effective treatment of CRC. Scientists are paying efforts to develop novel carrier systems that may enhance the targeting potential of low therapeutic index chemo- and immune-therapeutics. Several preclinical studies have revealed the superior efficacy of nanotherapy in CRC as compared to conventional approaches. Clinical trials are being recruited to ascertain the safety and efficacy of CRC therapies. The present review discourses in a nutshell the molecular interventions including the genetics, signaling pathways involved in CRC, and advances in various strategies explored for the treatment of CRC with a special emphasis on nanocarriers based drug targeting.

Recent Advances in Polymeric Implants

Implantable drug delivery systems, such as drug pumps and polymeric drug depots, have emerged as means of providing predetermined drug release profiles at the desired site of action. While initial implants aimed at providing an enduring drug supply, developments in polymer chemistry and pharmaceutical technology and the growing need for refined drug delivery patterns have prompted the design of sophisticated drug delivery implants such as on-demand drug-eluting implants and personalized 3D printed implants. The types of cargo loaded into these implants range from small drug molecules to hormones and even therapeutic cells. This review will shed light upon recent advances in materials and composites used for polymeric implant fabrication, highlight select approaches employed in polymeric implant fabrication, feature medical applications where polymeric implants have a significant impact, and report recent advances made in these areas.

Downregulation of lncRNA CCAT1 enhances 5-fluorouracil sensitivity in human colon cancer cells

BACKGROUND

The purpose of this study was to determine the aberrant expression of the long noncoding RNA (lncRNA) colon cancer-associated transcript 1 (CCAT1) in 5-fluorouracil-resistant colonic neoplasm cells and to elucidate its effects on the 5-fluorouracil sensitivity of human colonic neoplasm cells. The aberrant expression of lncRNAs in normal tissues and colonic neoplasm tissues was detected by microarray assay. qRT-PCR analysis was performed to assess CCAT1 expression levels in colonic neoplasm cell lines and corresponding normal tissues. After constructing the 5-FU-resistant cell lines and validating the resistance by measuring the IC₅₀ value, the CCAT1 expression levels in parental and artificially resistant cell lines were determined by qRT-PCR. Transfection was used to modulate the expression of CCAT1. Cell proliferation and apoptosis were then detected by CCK-8 and flow cytometry, respectively.

RESULTS

CCAT1 in colon cancer tissues was higher than that in noncancer tissues, and the levels of CCAT1 in HCT 116, SW1417, HT-29, and KM12 cell lines were higher than those in the human normal colon epithelial NCM460 cell line. Moreover, the expression levels of CCAT1 were high in HCT 116/5-FU and HT-29/5-FU cell lines, whose apoptosis rates induced by 5-FU were lower than those in corresponding parental cells. The results of qRT-PCR and CCK-8 assay showed that enhancement of lncRNA CCAT1 expression levels in HCT 116 and HT-29 cell lines increased their IC₅₀ of 5-FU and decreased their apoptosis rates. Meanwhile, siRNA-CCAT1 effectively inhibited the expression of CCAT1 and enhanced the 5-FU-sensitivity of HCT 116/5-FU and HT-29/5-FU, in which apoptosis rates were increased at the same time.

CONCLUSIONS

Downregulation of CCAT1 effectively reversed the resistance of HCT 116/5-FU and HT-29/5-FU cells to 5-FU chemotherapeutic, opening a new avenue in colon cancer therapy.

Non-aqueous formulations for ram and screen extrusion-spheronisation

The use of non-aqueous cellulose-based formulations for extrusion-spheronisation (E-S) is investigated. A 10 wt% hydroxypropyl cellulose/isopropyl alcohol solution (HPC/IPA) was identified as a suitable sticky liquid binder for preparing non-aqueous pastes. Preliminary tests were performed on a series of pastes using a ram as well as a laboratory roller screen extruder, since the former is commonly used in batch testing and the latter replicates the shear range in a manufacturing screen extruder. Pellets with acceptable size and shape distributions were obtained with Avicel® HFE-102 NF/HPC/IPA for ram E-S, and with Avicel® RC-591/HPC/IPA for screen E-S. Further investigation was performed with calcium carbonate added as a model active pharmaceutical ingredient. Both formulations were able to generate pellets with acceptable size and shape characteristics at up to 50 wt% carbonate loading: further work is required to optimise yields.

Recent Perspectives in Hot Melt Extrusion-Based Polymeric Formulations for Drug Delivery: Applications and Innovations

Hot melt extrusion (HME), a technology which mixing the advantages of solid dispersion technology and mechanical preparation, is accepted in varied applications in pharmaceutical formulations. When combined with other techniques, such as nanotechnique, three-dimensional printing, and co-extrusion, HME becomes much more multifunctional in the application of drug delivery. While in most cases, polymers employed in HME are responsible for the final property of products. The process of HME together with the selection of materials employed in HME were described briefly. In addition, the applications of HME in drug delivery and its currently status in the pharmaceutical field were also included. Some commercial products produced by HME have met the approval of FDA, indicating the commercial viability of this technique. Although showing great potential in pharmaceutical manufacturing, HME is still challenged by high temperature, shear force, and high input energy. Development of equipment, modifying the parameters, and optimization of polymeric formulations are needed for a safe, effective, and multifunctional hot melt extrusion drug delivery system. Also, wider range of combinations between HME and other techniques may provide guideline for developing multiple applications in drug delivery.

Green synthesis of multifunctional PEG-carboxylate π back-bonded gold nanoconjugates for breast cancer treatment

BACKGROUND

Surface functionalization of gold nanoparticles (AuNPs) has emerged as a promising field of research with enormous biomedical applications. The folate (FA)-attached polymer-gold nanoconjugates play vital role in targeting the cancer cells.

METHODS

AuNPs were synthesized by using di- or tri-carboxylate-polyethylene glycol (PEG) polymers, including citrate-PEG (CPEG), malate-PEG (MAP), and tartrate-PEG (TAP), as a reducing and stabilizing agent. After synthesis of polymer-AuNPs, the freely available hydroxyl and carboxylate groups of CPEG, MAP, and TAP were used to attach a cancer cell-targeting agent, FA, via a 1-Ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxy succinimide coupling reaction to obtain FA-CPEG-AuNP, FA-MAP-AuNP, and FA-TAP-AuNP nanocon-jugates, respectively. The 5-fluorouracil (5FU) was attached to π back-bonded carbonyl oxygens of the nanoconjugates, and the in vitro drug release profile was studied by high pressure liquid chromatography. Biocompatibility profiles of the FA-CPEG-AuNP, FA-MAP-AuNP, and FA-TAP-AuNP nanoconjugates were investigated using adult human dermal fibroblasts. Anti-breast cancer activity of 5FU-loaded nanoconjugates was investigated using MCF-7 breast cancer cells.

RESULTS

X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy analyses confirmed that AuNPs attached to CPEG, MAP, or TAP via the formation of π back bonding between AuNPs and the ester carbonyl group. The π back-bonded nanoconjugates exhibited sustained release of 5FU up to 27 days. FA-MAP-AuNPs exhibited an IC50 at 5 µg/mL, while FA-CPEG-AuNPs and FA-TAP-AuNPs showed the IC50 at 100 µg/mL toward MCF-7 cancer cells.

CONCLUSION

The developed polymer π back-bonded multifunctional gold nanoconjugates could be used as a potential drug delivery system for targeting MCF-7 cancer cells.

Nanoparticle-Based Delivery of CRISPR/Cas9 Genome-Editing Therapeutics

The recent progress in harnessing the efficient and precise method of DNA editing provided by CRISPR/Cas9 is one of the most promising major advances in the field of gene therapy. However, the development of safe and optimally efficient delivery systems for CRISPR/Cas9 elements capable of achieving specific targeting of gene therapy to the location of interest without off-target effects is a primary challenge for clinical therapeutics. Nanoparticles (NPs) provide a promising means to meet such challenges. In this review, we present the most recent advances in developing innovative NP-based delivery systems that efficiently deliver CRISPR/Cas9 constructs and maximize their effectiveness.