Finely tuned ionizable lipid nanoparticles for CRISPR/Cas9 ribonucleoprotein delivery and gene editing.

Nonviral delivery of the CRISPR/Cas9 system provides great benefits for in vivo gene therapy due to the low risk of side effects. However, in vivo gene editing by delivering the Cas9 ribonucleoprotein (RNP) is challenging due to the poor delivery into target tissues and cells. Here, we introduce an effective delivery method for the CRISPR/Cas9 RNPs by finely tuning the formulation of ionizable lipid nanoparticles. The LNPs delivering CRISPR/Cas9 RNPs (CrLNPs) are demonstrated to induce gene editing with high efficiencies in various cancer cell lines in vitro. Furthermore, we show that CrLNPs can be delivered into tumor tissues with high efficiency, as well as induce significant gene editing in vivo. The current study presents an effective platform for nonviral delivery of the CRISPR/Cas9 system that can be applied as an in vivo gene editing therapeutic for treating various diseases such as cancer and genetic disorders.

Effective Retinal Penetration of Lipophilic and Lipid-Conjugated Hydrophilic Agents Delivered by Engineered Liposomes.

Efficient delivery of drugs to the retina is critical but difficult to achieve with current methods. There have been a number of attempts to use intravitreal injection of liposomes, artificial vesicles composed of a phospholipid bilayer, to overcome the limitations of conventional intravitreal injection (short retention time, toxicity, poor penetration, etc.). Here, we report an optimal liposomal formulation that can diffuse through the vitreous humor, deliver the incorporated agents to all retinal layers effectively, and maintain them for a relatively long time. We first delivered lipophilic compounds and phospholipid-conjugated hydrophilic agents to the inner limiting membrane using engineered liposomes. Subsequently, the agents penetrated the retina deeply, presumably via extracellular vesicles, nanoscale vesicles secreted from retinal-associated cells. These results suggest that this engineered liposomal formulation can leverage the biological transport system for effective retinal penetration of lipophilic and lipid-conjugated agents.

Liposome-based engineering of cells to package hydrophobic compounds in membrane vesicles for tumor penetration.

Natural membrane vesicles (MVs) derived from various types of cells play an essential role in transporting biological materials between cells. Here, we show that exogenous compounds are packaged in the MVs by engineering the parental cells via liposomes, and the MVs mediate autonomous intercellular migration of the compounds through multiple cancer cell layers. Hydrophobic compounds delivered selectively to the plasma membrane of cancer cells using synthetic membrane fusogenic liposomes were efficiently incorporated into the membrane of MVs secreted from the cells and then transferred to neighboring cells via the MVs. This liposome-mediated MV engineering strategy allowed hydrophobic photosensitizers to significantly penetrate both spheroids and in vivo tumors, thereby enhancing the therapeutic efficacy. These results suggest that innate biological transport systems can be in situ engineered via synthetic liposomes to guide the penetration of chemotherapeutics across challenging tissue barriers in solid tumors.

Adsorption-desorption oscillations of nanoparticles on a honeycomb-patterned pH-responsive hydrogel surface in a closed reaction system.

A new type of pH-responsive hydrogel surface with varying nanoparticle adsorptivities was fabricated to form a micro-patterned film. To increase its responsivity to environmental pH changes, we incorporated graphene oxide (GO) into a poly(methacrylic acid)-polyethylene glycol copolymer. Incorporating GO in the pH-responsive hydrogel significantly increased the adsorption-desorption responsivity of Ag nanoparticles on the gel surface. A pH oscillator in a closed reaction system composed of BrO3(-)-Fe(CN)6(4-)-SO3(2-) facilitated the self-oscillating adsorption-desorption of Ag nanoparticles on the GO-incorporated gel surface. The reversible adsorption-desorption of Ag nanoparticles on the patterned hydrogel surface in response to pH oscillations was determined using UV-visible spectroscopy in aqueous solution. The observed heterogeneous oscillations indicated that the adsorptivity of the gel surface can be reversibly changed on the patterned pH-responsive gel. This phenomenon is similar to various natural biological systems.

A One-Year Randomized Controlled Clinical Trial of Three Types of Narrow-Diameter Implants for Fixed Partial Implant-Supported Prosthesis in the Mandibular Incisor Area.

Narrow-diameter implants (NDI) serve as a solution for treating limited bone volume in the anterior mandible. This study aimed to evaluate the one-year clinical outcomes of various NDIs in the mandibular incisor area after immediate loading in partially edentulous patients. This single-center, prospective, single-blinded, randomized controlled trial study included 21 patients, with 7 patients in each of the following groups: control (BLT NC SLActive®; Straumann), experimental group 1 (CMI IS-III Active® S-Narrow; Neobiotech), and experimental group 2 (CMI IS-III Active® Narrow; Neobiotech). Using full digital flow, two fixtures were placed in each patient and immediately provisionalized on the day of surgery. Evaluations encompassed periapical radiographs, implant stability quotient (ISQ), implant stability test (IST) readings, per-implant soft tissue health, patient satisfaction surveys, and esthetic score assessments. Definitive prostheses were delivered twelve weeks post-surgery (CRiS, number: KCT0007300). Following exclusions due to low stability values (n = 2), fixture failure (n = 5), and voluntary withdrawal (n = 1), the implant success rate for patients completing all clinical protocols stood at 100%. The resulting patient failure rates in the control, experimental group 1, and experimental group 2 were 50.0%, 42.9%, and 14.3%, respectively. There were no significant differences between the groups in terms of marginal bone loss, soft tissue health, patient satisfaction, and esthetic scores. Narrow implants showed superior clinical outcomes, followed by S-Narrow and Straumann implants. Calculated one-year survival rates at the implant level were 66.7% for the control group, 85.7% for experimental group 1, and 100% for experimental group 2. All three types of NDIs showed acceptable clinical and radiographic results during the year-long observation period.

Tailoring photobiomodulation to enhance tissue regeneration.

Photobiomodulation (PBM), the use of biocompatible tissue-penetrating light to interact with intracellular chromophores to modulate the fates of cells and tissues, has emerged as a promising non-invasive approach to enhancing tissue regeneration. Unlike photodynamic or photothermal therapies that require the use of photothermal agents or photosensitizers, PBM treatment does not need external agents. With its non-harmful nature, PBM has demonstrated efficacy in enhancing molecular secretions and cellular functions relevant to tissue regeneration. The utilization of low-level light from various sources in PBM targets cytochrome c oxidase, leading to increased synthesis of adenosine triphosphate, induction of growth factor secretion, activation of signaling pathways, and promotion of direct or indirect gene expression. When integrated with stem cell populations, bioactive molecules or nanoparticles, or biomaterial scaffolds, PBM proves effective in significantly improving tissue regeneration. This review consolidates findings from in vitro, in vivo, and human clinical outcomes of both PBM alone and PBM-combined therapies in tissue regeneration applications. It encompasses the background of PBM invention, optimization of PBM parameters (such as wavelength, irradiation, and exposure time), and understanding of the mechanisms for PBM to enhance tissue regeneration. The comprehensive exploration concludes with insights into future directions and perspectives for the tissue regeneration applications of PBM.

Room temperature phosphorescence of metal-free organic materials in amorphous polymer matrices.

Developing metal-free organic phosphorescent materials is promising but challenging because achieving emissive triplet relaxation that outcompetes the vibrational loss of triplets, a key process to achieving phosphorescence, is difficult without heavy metal atoms. While recent studies reveal that bright room temperature phosphorescence can be realized in purely organic crystalline materials through directed halogen bonding, these organic phosphors still have limitations to practical applications due to the stringent requirement of high quality crystal formation. Here we report bright room temperature phosphorescence by embedding a purely organic phosphor into an amorphous glassy polymer matrix. Our study implies that the reduced beta (ß)-relaxation of isotactic PMMA most efficiently suppresses vibrational triplet decay and allows the embedded organic phosphors to achieve a bright 7.5% phosphorescence quantum yield. We also demonstrate a microfluidic device integrated with a novel temperature sensor based on the metal-free purely organic phosphors in the temperature-sensitive polymer matrix. This unique system has many advantages: (i) simple device structures without feeding additional temperature sensing agents, (ii) bright phosphorescence emission, (iii) a reversible thermal response, and (iv) tunable temperature sensing ranges by using different polymers.

Bone graft using block allograft as a treatment of failed implant sites: clinical case reports.

Alveolar bone should be augmented to an adequate height and width for an implant to have satisfactory functional, biological, and aesthetic properties. Large osseous defects often require block grafts harvested from the symphysis or ramus. However, surgical complications and the necessity of donor sites have led to using allogeneic grafting materials. Two patients with severe bone defects on their mandibular posterior and maxillary posterior teeth were selected to be the subjects of this study. These 2 patients needed their implant fixtures removed due to implant failure. They received alveolar ridge augmentation using commercial block allografts, and after an integration period of several months, an implant was placed. The short-term results suggest that block allografts may be suitable bone-replacement materials for augmenting alveolar defects, especially for bone grafts in bone defect areas caused by removing failed implants.

Clinical application of platelet-rich fibrin by the application of the Double J technique during implant placement in alveolar bone defect areas: case reports.

Platelet-rich fibrin (PRF) belongs to a new generation of platelet concentrates, with simplified processing and without biochemical blood handling. PRF releases growth factors and matrix glycoproteins. In this study, the Double J technique was used. The Double J technique, which uses centrifuged venous blood that is sampled using 2 different types of DB vacutainers, is a procedure that covers the PRF matrix obtained from 1 of the DB vacutainers on transplanted osseous coagulum, which is obtained using the plasma layer and buffering layer from the second DB vacutainer. Two cases were reported because clinically valid results were obtained. Additional studies are definitely warranted.

Comprehensive experimental and theoretical investigations on the effect of microbubble two-phase flow on the performance of direct-contact membrane distillation.

This study provides a comprehensive and systematic overview of the application of gas-liquid two-phase flow with microbubbles in the feed stream to improve heat and mass transfer in direct-contact membrane distillation (DCMD) processes for seawater desalination. A swirl-flow-type microbubble generator (MBG) was installed at the feed-side inlet of the DCMD module to investigate its effect on transmembrane flux. The maximum improvement in the MBG-assisted DCMD permeation flux was found to be approximately 18% at a lower feed temperature (40 °C) and optimal air flow rate (50 cc/min), and an optimal MBG geometry comprising a swirler, a nozzle tip of diameter 2 mm, and a diffuser at an angle of 30°. The results were observed to be related to the number density of microbubbles less than 100 µm in size, which plays an important role in improving heat and mass transfer in two-phase flow. In addition, the simulation results based on conventional heat transfer correlations of bubbly flow underestimated the experimental results. Therefore, this study also aims to propose and verify a new two-phase flow heat transfer correlation. The proposed correlation considers the effects of bubble size distribution to accurately predict the performance of MBG-assisted DCMD processes.

Targeted Fusogenic Liposomes for Effective Tumor Delivery and Penetration of Lipophilic Cargoes.

Nanoparticle-based drug delivery has been widely used for effective anticancer treatment. However, a key challenge restricting the efficacy of nanotherapeutics is limited tissue penetration within solid tumors. Here, we report a targeted fusogenic liposome (TFL) that can selectively deliver lipophilic cargo to the plasma membranes of tumor cells. TFL is prepared by directly attaching tumor-targeting peptides to the surface of FL instead of the cationic moieties. The lipophilic cargo loaded in the membrane of TFL is transferred to the plasma membranes of tumor cells and subsequently packaged in the extracellular vesicles (EVs) released by the cells. Systemically administered TFL accumulates in the perivascular region of tumors, where the lipophilic cargo is unloaded to the tumor cell membranes and distributed autonomously throughout the tumor tissue via extracellular vesicle-mediated intercellular transfer. When loaded with a lipophilic pro-apoptotic drug, thapsigargin (Tg), TFL significantly inhibits tumor growth in a mouse colorectal cancer model. Furthermore, the combination treatment with TFL (Tg) potentiates the antitumor efficacy of FDA-approved liposomal doxorubicin, whose therapeutic effect is limited to perivascular regions without significant toxicity.

Different effect of hydrogelation on antifouling and circulation properties of dextran-iron oxide nanoparticles.

Premature recognition and clearance of nanoparticulate imaging and therapeutic agents by macrophages in the tissues can dramatically reduce both the nanoparticle half-life and delivery to the diseased tissue. Grafting nanoparticles with hydrogels prevents nanoparticulate recognition by liver and spleen macrophages and greatly prolongs circulation times in vivo. Understanding the mechanisms by which hydrogels achieve this "stealth" effect has implications for the design of long-circulating nanoparticles. Thus, the role of plasma protein absorption in the hydrogel effect is not yet understood. Short-circulating dextran-coated iron oxide nanoparticles could be converted into stealth hydrogel nanoparticles by cross-linking with 1-chloro-2,3-epoxypropane. We show that hydrogelation did not affect the size, shape and zeta potential, but completely prevented the recognition and clearance by liver macrophages in vivo. Hydrogelation decreased the number of hydroxyl groups on the nanoparticle surface and reduced the binding of the anti-dextran antibody. At the same time, hydrogelation did not reduce the absorption of cationic proteins on the nanoparticle surface. Specifically, there was no effect on the binding of kininogen, histidine-rich glycoprotein, and protamine sulfate to the anionic nanoparticle surface. In addition, hydrogelation did not prevent activation of plasma kallikrein on the metal oxide surface. These data suggest that (a) a stealth hydrogel coating does not mask charge interactions with iron oxide surface and (b) the total blockade of plasma protein absorption is not required for maintaining iron oxide nanoparticles' long-circulating stealth properties. These data illustrate a novel, clinically promising property of long-circulating stealth nanoparticles.

Surface-modified gemcitabine with mucoadhesive polymer for oral delivery.

Gemcitabine microparticles were prepared using chitosan, polyethylene oxide or carbopol as the mucoadhesive polymer and eudragit L100-55 as the enteric polymer by a double emulsion method. The particle size and zeta potential changed from 1338.3 ± 254.1 nm to 2459.4 ± 103.6 nm and -5.16 ± 1.62 mV to 2.84 ± 0.65 mV, respectively, with increasing chitosan to gemcitabine weight ratio from 0.25 to 1. The gemcitabine-loaded microparticles without mucoadhesive polymer (F50) showed the particle size and zeta potential of 671.3 ± 58.3 nm and - 16.7 ± 1.82 mV, respectively. The cellular uptake of gemcitabine into Caco-2 cells from gemcitabine-loaded microparticles with chitosan increased with increasing incubation time in Caco-2 cells compared to that of gemcitabine-loaded microparticles with polyethylene oxide or carbopol, suggesting that chitosan might be the optimal mucoadhesive polymer. Gemcitabine microparticles will be tested to identify whether the oral absorption could be increased in the future.

Height-Tunable Replica Molding Using Viscous Polymeric Resins.

Replica molding is one of the most common and low-cost methods for constructing microstructures for various applications, including dry adhesives, optics, tissue engineering, and strain sensors. However, replica molding provides only a single-height microstructure from a mold and master molds produced by an expensive photolithography process are required to prepare microstructures with different heights. Herein, we present a strategy to control the height of micropillars from the same mold by varying the cavity size of the micromold and the viscosity of the photocurable polyimide resin. The height of the constructed micropillar decreases in the case of small microcavities or high viscosity resin. In addition, the height of the micropillar arrays could be arbitrarily patterned by applying a masking technique. We believe that this cost-effective technique can be applied to metasurfaces for manipulation of electromagnetic signal or in biomedical applications including cell-culture and stem-cell differentiation.

Enteric Polymer-Coated Porous Silicon Nanoparticles for Site-Specific Oral Delivery of IgA Antibody.

Porous silicon (pSi) nanoparticles are loaded with Immunoglobulin A-2 (IgA2) antibodies, and the assembly is coated with pH-responsive polymers on the basis of the Eudragit family of enteric polymers (L100, S100, and L30-D55). The temporal release of the protein from the nanocomposite formulations is quantified following an in vitro protocol simulating oral delivery: incubation in simulated gastric fluid (SGF; at pH 1.2) for 2 h, followed by a fasting state simulated intestinal fluid (FasSIF; at pH 6.8) or phosphate buffer solution (PBS; at pH 7.4). The nanocomposite formulations display a negligible release in SGF, while more than 50% of the loaded IgA2 is released in solutions at a pH of 6.8 (FasSIF) or 7.4 (PBS). Between 21 and 44% of the released IgA2 retains its functional activity. A capsule-based system is also evaluated, where the IgA2-loaded particles are packed into a gelatin capsule and the capsule is coated with either EudragitL100 or EudragitS100 polymer for a targeted release in the small intestine or the colon, respectively. The capsule-based formulations outperform polymer-coated nanoparticles in vitro, preserving 45-54% of the activity of the released protein.

Intense focused ultrasound tightening in Asian skin: clinical and pathologic results.

BACKGROUND: Laxity and wrinkles of the aging face are common cosmetic concerns. Intense focused ultrasound (IFUS), a novel treatment modality for skin laxity, produces thermal effects at various depths while sparing overlying epidermis. OBJECTIVE: To evaluate the safety and efficacy of IFUS in facial skin tightening. METHODS AND MATERIALS: Twenty-two Korean patients with facial laxity were analyzed after a single IFUS treatment. Patient assessments were recorded, and two blinded, experienced clinicians who assessed improvement of nasolabial folds and jaw tightening evaluated photographs of patients and rated skin laxity. Skin biopsies were taken from 11 patients before and 2 months after treatment. RESULTS: Objectively, nasolabial folds and jaw lines were improved in all patients. Subjectively, 77% of patients reported much improvement of nasolabial folds, and 73% of patients reported much improvement at the jaw line. Histologic evaluation of skin biopsy samples using hematoxylin and eosin and Victoria blue stains showed greater dermal collagen with thickening of the dermis and straightening of elastic fibers in the reticular dermis after treatment. CONCLUSION: IFUS is a safe, effective, noninvasive procedure to tighten the facial skin of Asian patients. Improvement is associated with greater production of dermal collagen and straightening of dermal elastic fibers.

The impacts of open-mouth breathing on upper airway space in obstructive sleep apnea: 3-D MDCT analysis.

Open-mouth breathing during sleep is a risk factor for obstructive sleep apnea (OSA) and is associated with increased disease severity and upper airway collapsibility. The aim of this study was to investigate the effect of open-mouth breathing on the upper airway space in patients with OSA using three-dimensional multi-detector computed tomography (3-D MDCT). The study design included a case-control study with planned data collection. The study was performed at a tertiary medical center. 3-D MDCT analysis was conducted on 52 patients with OSA under two experimental conditions: mouth closed and mouth open. Under these conditions, we measured the minimal cross-sectional area of the retropalatal and retroglossal regions (mXSA-RP, mXSA-RG), as well as the upper airway length (UAL), defined as the vertical dimension from hard palate to hyoid. We also computed the volume of the upper airway space by 3-D reconstruction of both conditions. When the mouth was open, mXSA-RP and mXSA-RG significantly decreased and the UAL significantly increased, irrespective of the severity of OSA. However, between the closed- and open-mouth states, there was no significant change in upper airway volume at any severity of OSA. Results suggest that the more elongated and narrow upper airway during open-mouth breathing may aggravate the collapsibility of the upper airway and, thus, negatively affect OSA severity.

Midterm results of primary total hip arthroplasty using highly cross-linked polyethylene: minimum 7-year follow-up study.

The purpose of this study was to investigate the results of 113 total hip arthroplasties in 109 patients using highly cross-linked polyethylene (HXLPE) after midterm (minimum 7 years) follow-up retrospectively. The mean age at the time of operation was 57 years. Preoperative diagnosis was osteonecrosis in 81 hips and other diagnosis in 32 hips. There was no component loosening. Acetabular osteolysis was found in 12 hips (10.6 %). Mean linear HXLPE wear rate was 0.031 ± 0.012 mm/y. We analyzed the relationship between HXLPE wear rate and several variables influencing HXLPE wear. Only the cup position was related with wear rate of HXLPE significantly (P < .05). The results of total hip arthroplasties using HXLPE showed excellent results with decreased wear rate and low incidence of osteolysis after midterm follow-up.

Hemorrhage related to implant placement in the anterior mandible.

Implant placement in the edentulous anterior mandible is relatively considered a routine and safe procedure. The interforaminal area is the usual area in the mandible for implant placement for the support and retention of a fixed partial denture or removable overdenture. This region is also the usual donor site of bone grafts. However, implant placement, like any other surgical procedure, is not free of risks and complications. The purpose of this review article was to investigate the risk of a life threatening hemorrhage due to arterial injury at implant placement in the anterior mandible.

Biodegradable luminescent porous silicon nanoparticles for in vivo applications.

Nanomaterials that can circulate in the body hold great potential to diagnose and treat disease. For such applications, it is important that the nanomaterials be harmlessly eliminated from the body in a reasonable period of time after they carry out their diagnostic or therapeutic function. Despite efforts to improve their targeting efficiency, significant quantities of systemically administered nanomaterials are cleared by the mononuclear phagocytic system before finding their targets, increasing the likelihood of unintended acute or chronic toxicity. However, there has been little effort to engineer the self-destruction of errant nanoparticles into non-toxic, systemically eliminated products. Here, we present luminescent porous silicon nanoparticles (LPSiNPs) that can carry a drug payload and of which the intrinsic near-infrared photoluminescence enables monitoring of both accumulation and degradation in vivo. Furthermore, in contrast to most optically active nanomaterials (carbon nanotubes, gold nanoparticles and quantum dots), LPSiNPs self-destruct in a mouse model into renally cleared components in a relatively short period of time with no evidence of toxicity. As a preliminary in vivo application, we demonstrate tumour imaging using dextran-coated LPSiNPs (D-LPSiNPs). These results demonstrate a new type of multifunctional nanostructure with a low-toxicity degradation pathway for in vivo applications.